JP5304033B2 - Manufacturing method of semiconductor device - Google Patents

Abstract

A method of manufacturing the semiconductor device is provided to improve the dielectric constant of the silica-based insulating layer caused by the process damage and to obtain the insulating layer having high reliability. The insulating layer of the silica-based insulating material is formed on the semiconductor substrate. The insulating layer is processed by the dry etching. The processed insulating layer is hydrophobic by reacting the processed insulating layer with the silane compound(S14). At this time, the silane compound reacts to the Si-OH bonding introduced by the damage of the dry etching within the insulating layer. The resultant insulating layer is irradiated by the light or the electron beam and the Si-OH bonding(S15).

Description

  The present invention relates to a method for manufacturing a semiconductor device, and more particularly to a method for manufacturing a semiconductor device including a step of processing a silica-based insulating film.

  With the increase in the degree of integration of semiconductor integrated circuits and the increase in element density, there is an increasing demand for multilayer semiconductor elements. On the other hand, with high integration, the wiring interval is narrowed, and wiring delay due to increased capacitance between wirings has become a problem.

The wiring delay T is affected by the wiring resistance and the capacitance between the wirings. When the wiring resistance is R and the capacitance between the wirings is C,
T ∝ CR
Represented as: In this equation, when the wiring interval is represented by d, the electrode area (side area of the facing wiring) is represented by S, the dielectric constant of the insulating material provided between the wirings is represented by ε _r , and the vacuum dielectric constant is represented by ε _0. The capacity C between
C = ε ₀ ε _r S / d
Represented as: Therefore, reducing the dielectric constant of the insulating film is an effective means for reducing the wiring delay.

Conventionally, as an insulating material, an inorganic film such as silicon dioxide (SiO ₂ ), silicon nitride (SiN), phosphosilicate glass (PSG), or an organic polymer such as polyimide has been used. However, the dielectric constant of the CVD-SiO ₂ film most used in semiconductor devices is about 4. Moreover, although the SiOF film | membrane currently examined as a low dielectric constant CVD film | membrane has a dielectric constant of about 3.3-3.5, a hygroscopic property is high and a dielectric constant will raise with moisture absorption.

  Furthermore, in recent years, a porous insulating film has attracted attention as an insulating material having a lower relative dielectric constant. The porous insulating film is obtained by adding an organic resin or the like that evaporates or decomposes by heating to a material for forming a low dielectric constant film, and evaporates or decomposes it by heating at the time of film formation to make it porous.

Silica-based insulating films, particularly porous insulating films, are subject to processing damage in the process of forming a multilayer wiring, and the effective dielectric constant sometimes increases. For this, a method has been proposed in which the damaged layer is recovered by subjecting the surface of the interlayer insulating film after dry etching to surface treatment with a silazane compound and then drying under reduced pressure. Further, a method for recovering a damaged layer by treating an insulating film with silazane or a silane compound such as alkoxysilane or acetoxysilane has been proposed.
Japanese translation of PCT publication No. 2004-511896 JP 2005-217143 A JP 2005-340288 A JP 2006-104418 A JP 2006-203060 A JP 2006-073800 A Japanese Patent Laid-Open No. 2006-190962 JP 2004-277463 A JP 2000-188331 A Japanese translation of PCT publication No. 2004-511896 JP 2006-049798 A JP 2006-086411 A

  However, as a result of studies by the inventors of the present application, it has been found that the dielectric constant of the processed insulating film is recovered immediately after the surface treatment, but rises again after being left in the atmosphere for about one week.

  An object of the present invention relates to a method of manufacturing a semiconductor device using a silica-based insulating film, and can recover an increase in dielectric constant due to processing damage of the silica-based insulating film and prevent an increase in dielectric constant due to leaving in the atmosphere. Another object of the present invention is to provide a method for manufacturing a semiconductor device.

According to one aspect of the embodiment, a step of forming an insulating film of a silica-based insulating material on a semiconductor substrate, a step of processing the insulating film, and a silane compound acting on the processed insulating film There is provided a method for manufacturing a semiconductor device , comprising a step of hydrophobizing and a step of performing light irradiation or electron beam irradiation on the insulating film after the step of hydrophobizing the insulating film.

According to another aspect of the embodiment, a step of forming an insulating film of a silica-based insulating material on a semiconductor substrate, a step of forming an opening in the insulating film by dry etching, and the opening Forming a conductive film on the insulating film in which the portion is formed, removing the conductive film on the insulating film by polishing, and forming a wiring including the conductive film embedded in the opening; And hydrophobizing the insulating film by acting a silane compound between at least one of the step of forming the opening and the step of forming the conductive film and after the step of forming the wiring. There is provided a method for manufacturing a semiconductor device, further comprising a step of performing a light irradiation or an electron beam irradiation on the insulating film after the step of hydrophobizing the insulating film.

  According to the disclosed method for manufacturing a semiconductor device, an increase in the dielectric constant of the insulating film due to processing damage can be recovered, and an increase in the dielectric constant due to leaving in the atmosphere can be prevented. Thereby, an insulating film having a low dielectric constant and high reliability can be obtained. Further, by applying this insulating film to, for example, an interlayer insulating film having a multilayer wiring structure, the response speed of the semiconductor device can be increased.

[First Embodiment]
A method of manufacturing a semiconductor device according to the first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a flowchart showing a method for manufacturing a semiconductor device according to the present embodiment, and FIGS. 2 and 3 are process cross-sectional views showing the method for manufacturing a semiconductor device according to the present embodiment.

  As shown in FIG. 1, the semiconductor device manufacturing method according to the present embodiment includes a step of depositing a silica-based insulating film (step S11), a step of patterning the silica-based insulating film (step S12), and a side wall by plasma processing. A step of removing deposits (step S13), a step of repairing dry etching damage with a silane compound (step S14), a step of performing a condensation process of Si—OH by light irradiation or electron beam irradiation (step S15), have.

  Hereinafter, each step will be described in detail with reference to FIGS. 2 and 3.

  First, a silica-based insulating film 102 is formed on the base substrate 100 (step S11). Note that the base substrate 100 includes not only a semiconductor substrate itself such as a silicon substrate but also a semiconductor substrate on which an MIS transistor and other elements and one or more wiring layers are formed.

Examples of the silica-based insulating film 102 include plasma CVD films such as plasma SiO ₂ film, plasma SiN film, plasma SiC: H film, plasma SiC: O: H film, plasma SiC: H: N film, and plasma SiOC film. A coating type insulating film such as an organic SOG film or porous silica can be applied. The SiC: H film is a film in which H (hydrogen) is present in the SiC film. The SiC: O: H film is a film in which O (oxygen) and H (hydrogen) are present in the SiC film. The SiC: H: N film is a film in which H (hydrogen) and N (nitrogen) are present in the SiC film. Of these, a coating type insulating film such as porous silica is preferable from the viewpoint that the dielectric constant of the material alone is low.

  As porous silica, for example, a thermal decomposable resin is added to organic SOG, and it is thermally decomposed by heating to form a void, and silica particles are formed in an alkali and the gap between the particles is used. And non-template type in which holes are formed. Among these, the non-plate type that can form fine pores uniformly is preferable.

  Examples of the non-plate type porous silica material include NCS series manufactured by Catalytic Chemical Industry Co., Ltd. and LKD series manufactured by JSR Co., Ltd.

  As another non-template type porous silica material, for example, a liquid composition containing an organosilicon compound obtained by hydrolysis in the presence of tetraalkylammonium hydroxide (TAAOH) is suitable. This material has an elastic modulus of 10 GPa or more and a hardness of 1 GPa or more, and can achieve both low dielectric constant and high strength. Examples of the organosilicon compound include tetraalkoxysilane, trialkoxysilane, methyltrialkoxysilane, ethyltrialkoxysilane, propyltrialkoxysilane, phenyltrialkoxysilane, vinyltrialkoxysilane, allyltrialkoxysilane, and glycidyltrialkoxysilane. , Dialkoxysilane, dimethyl dialkoxysilane, diethyl dialkoxysilane, dipropyl dialkoxysilane, diphenyl dialkoxysilane, divinyl dialkoxysilane, diallyl dialkoxysilane, diglycidyl dialkoxysilane, phenylmethyl dialkoxysilane, phenylethyl Dialkoxysilane, phenylpropyltrialkoxysilane, phenylvinyldialkoxysilane, phenylallyldia Kokishishiran, phenyl glycidyl dialkoxysilane, can be applied methylvinyl dialkoxysilane, ethylvinyl dialkoxysilane, propyl vinyl dialkoxy silane.

  The coating solution used for forming the coating-type porous silica film is not particularly limited as long as it can dissolve the siloxane resin as the porous silica precursor, methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol, isobutyl. Alcohols such as alcohol, tert-butyl alcohol, phenols such as phenol, cresol, diethylphenol, triethylphenol, propylphenol, nonylphenol, vinylphenol, allylphenol, nonylphenol, ketones such as cyclohexanone, methylisobutylketone, methylethylketone, Cellosolves such as methyl cellosolve and ethyl cellosolve, hydrocarbons such as hexane, octane and decane, propylene glycol, propylene Glycol monomethyl ether, or the like can be used glycol such as propylene glycol monomethyl ether acetate.

  The insulating film using the coating-type insulating material includes, for example, a step of applying the insulating material on a base substrate, a step of heat-treating the base substrate at a temperature of 80 to 350 ° C., and a base substrate of 350 to And a step of curing at a temperature of 450 ° C. Note that the step of heat-treating the substrate at a temperature of 80 to 350 ° C. and the step of curing the substrate at a temperature of 350 to 450 ° C. are preferably performed in an inert gas atmosphere having an oxygen concentration of 100 ppm or less. This is to prevent a decrease in moisture resistance due to oxidation of the insulating film.

Next, a hard mask 104 of, eg, SiO ₂ is formed on the insulating film 102 by, eg, CVD (FIG. 2A).

  Next, a photoresist film 106 having an opening 108 in a predetermined region is formed on the hard mask 104 by photolithography.

  Next, the hard mask 104 is dry-etched using the photoresist film 106 as a mask, and the pattern of the opening 108 of the photoresist film 106 is transferred to the hard mask 104 (FIG. 2B).

  Next, the photoresist film 106 is removed by, for example, ashing using oxygen plasma.

Next, the insulating film 102 is dry-etched using the patterned hard mask 104 as a mask to form an opening 110 in the insulating film 102 (step S12). The dry etching of the insulating film 102 is not particularly limited as long as a wiring groove or a via hole can be formed in the silica-based insulating film. For example, a fluorine-containing gas such as CF ₄ , CHF ₃ , C ₂ F ₆ , C ₃ F ₈ , C ₄ F ₁₀ , or a mixed gas thereof, or argon (Ar), nitrogen (N ₂ ), A gas mixed with oxygen (O ₂ ), hydrogen (H ₂ ), or the like can be formed into plasma in a vacuum chamber, for example, under conditions of a pressure of 50 mTorr and a power of 200 W.

  In this dry etching process, a damage layer 112 is formed on the side wall portion of the opening 110 of the insulating film 102 (a region marked with x in the drawing). The damaged layer 112 is a region where the bond is broken by plasma damage and is in a state in which moisture is easily adsorbed, and Si—OH bonds are generated in the damaged layer 112.

In addition, by-products generated in the dry etching process may be deposited on the side wall portion of the opening 110 of the insulating film 102 to form a side wall deposit 114 (FIG. 2C). For example, when a silica-based insulating film is dry-etched using a fluorine-based etching gas, a CF _x polymer-based sidewall deposit 114 adheres to the sidewall portion of the opening 110.

  Next, if necessary, the patterned insulating film 102 is processed with plasma containing oxygen, argon, hydrogen, nitrogen, or a plurality of these gases (step S13). Thereby, the sidewall deposit 114 formed on the sidewall portion of the opening 110 can be removed (FIG. 3A).

  This plasma treatment is for removing the sidewall deposit 114. If the side wall deposit 114 remains on the side wall portion of the opening 110, the effect of the damage repair process in the subsequent process cannot be sufficiently obtained. Therefore, it is desirable to perform this plasma treatment for the dry etching of the insulating film 102 particularly when a fluorine-based etching gas is used.

  In the above process, the insulating film 102 is patterned using the hard mask 104 to which the pattern of the photoresist film 106 is transferred. However, the insulating film 102 is patterned using the photoresist film 106 as a direct mask without using the hard mask 104. You may make it do. In this case, the photoresist film 106 is removed after the opening 110 is formed. However, since the photoresist film 106 is usually removed by ashing with oxygen plasma, the same effect as in step S13 can be expected. In the case where the sidewall deposit 114 is sufficiently removed simultaneously with the ashing of the photoresist film 106, the plasma treatment in step S13 is not necessarily required. In addition to ashing with oxygen plasma, the plasma treatment in step S13 may be performed.

  Further, instead of performing the plasma treatment in step S13, the sidewall deposit 114 may be removed using a chemical solution such as hydrofluoric acid, ammonium fluoride, or ammonium phosphate.

  Next, using a silane compound, a treatment for repairing damage introduced by dry etching when the opening 110 is formed in the insulating film 102 is performed (step S14). By this treatment, the damage of the damage layer 112 on the side wall portion of the opening 110 of the insulating film 102 is repaired (the repair layer 116 in the figure) (FIG. 3B).

  Specifically, this treatment is for reacting Si—OH produced by damage during dry etching with a silane compound. The treatment is not particularly limited as long as it is a treatment capable of reacting Si-OH with a silane compound, and preferably a spin coating method, a vapor method in which the silane compound is treated as described above under normal pressure or vacuum, and the like. Can be applied. Among these, the vapor method which is not easily affected by the surface tension is more preferable.

  In the vapor method, it is desirable to heat the substrate temperature to 50 to 350 ° C. in order to diffuse the silane compound into the insulating film 102 and strengthen the repaired portion. In the spin coating method, the treatment is performed at room temperature by a spin coater, but a baking treatment may be performed after the spin coating in order to strengthen the repaired portion. In this case, it is desirable to perform baking at a single or plural temperatures in the range of 50 to 350 ° C.

  It is desirable that the treatment temperature is appropriately selected in the temperature range of 50 to 350 ° C. according to the type of the silane compound. The upper limit of the treatment temperature is mainly defined by the boiling point of the silane compound and is set to a temperature equal to or lower than the boiling point of the silane compound. The lower limit of the treatment temperature is set to 50 ° C. because the effect of repairing damage by the silane compound cannot be sufficiently obtained at a temperature lower than that.

  The silane compound applicable to the damage repair treatment is not particularly limited as long as it contains a functional group that reacts with Si-OH generated by damage during dry etching. For example, dimethyldisilazane, tetramethyldisilazane Silazane compounds such as hexamethyldisilazane, silylamide compounds such as bis (trimethylsilyl) acetamide and bis (triethylsilyl) acetamide, trimethoxysilane, triethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethylmethoxysilane, dimethyl Ethoxysilane, trimethylmethoxysilane, trimethylethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, diethylmethoxysilane, diethylethoxysilane, triethylmethoxysilane , Triethylethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, dipropylmethoxysilane, dipropylethoxysilane, tripropylmethoxysilane, tripropylethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, diphenylmethoxysilane, Alkoxysilane compounds such as diphenylethoxysilane, triphenylmethoxysilane, triphenylethoxysilane, phenylmethylmethoxysilane, phenylmethylethoxysilane, dimethylphenylmethoxysilane, dimethylphenylethoxysilane, diphenylmethylmethoxysilane, diphenylmethylethoxysilane, Acetoxysilane, triethoxysilane, methyltriethoxysilane, dimethylacetoxysila , Trimethylacetoxysilane, ethyltriethoxysilane, diethylacetoxysilane, triethylacetoxysilane, dipropylacetoxysilane, tripropylacetoxysilane, phenyltriacetoxysilane, diphenylacetoxysilane, triphenylacetoxysilane, phenylmethylacetoxysilane, dimethylphenylacetoxy Acetoxysilane compounds such as silane and diphenylmethylacetoxysilane can be used.

By the damage repair process described above, Si—OH in the damage layer 112 becomes Si—CH ₃ , and hydrophobicity can be increased. However, a large molecular mass of the silane compound becomes a steric hindrance, and it is difficult to convert all Si—OH into Si—CH ₃ . As a result, if the substrate is left in the air as it is, moisture is gradually adsorbed to Si—OH, causing an increase in the dielectric constant of the insulating film 102.

  Therefore, in the method for manufacturing the semiconductor device according to the present embodiment, after the damage repair process using the silane compound, the remaining Si—OH is condensed (dehydrated) to form Si—O—Si bonds, thereby forming Si The moisture is prevented from being adsorbed to -OH (step S15). The Si—OH condensation treatment can be realized by performing light irradiation or electron beam irradiation treatment while heating the substrate to 30 to 400 ° C. (FIG. 3C).

  The condensation treatment by light irradiation is not particularly limited as long as light having a wavelength of 170 to 700 nm can be irradiated. For example, an excimer lamp, a mercury lamp, and a metal can be a ride lamp. The substrate temperature during light irradiation is preferably 30 to 400 ° C.

  The atmosphere preferably has an oxygen concentration of 150 ppm or less, and nitrogen, helium (He), argon, a plurality of these gases, or a vacuum can be used. When performing in vacuum (under reduced pressure), nitrogen, helium, argon, or a plurality of these gases are introduced while controlling the pressure in the vacuum chamber to a predetermined pressure using a mass flow meter or the like. You may do it.

  In the condensation treatment by electron beam irradiation, it is desirable to irradiate an electron beam having an acceleration voltage of 1 to 15 kV in a vacuum. This is because if the acceleration voltage is less than 1 kV, a sufficient effect cannot be expected, and if the acceleration voltage is higher than 15 kV, the insulating film may be damaged.

  It is desirable that the treatment temperature at the time of light irradiation or electron beam irradiation is appropriately selected in the temperature range of 30 to 400 ° C. according to the type of the silica-based insulating film. The upper limit of the processing temperature is mainly defined by the heat-resistant temperature of the silica-based insulating film that forms the insulating film, and is set to a temperature lower than the heat-resistant temperature of the silica-based insulating film. The lower limit of the treatment temperature is 30 ° C. because the condensation reaction does not sufficiently occur at a temperature lower than that.

  Thus, by performing the Si—OH condensation treatment after the damage repair treatment with the silane compound, the hygroscopicity of the insulating film can be significantly reduced. Thereby, the adsorption | suction of the water | moisture content accompanying leaving to air | atmosphere is reduced significantly, and it can prevent effectively that a dielectric constant raises by adsorption | suction of a water | moisture content.

  As described above, according to the present embodiment, it is possible to recover the increase in the dielectric constant of the insulating film due to processing damage during dry etching and to prevent the increase in the dielectric constant due to being left in the atmosphere.

[Second Embodiment]
A method for fabricating a semiconductor device according to the second embodiment of the present invention will be described with reference to FIGS. Components similar to those of the semiconductor device manufacturing method according to the first embodiment shown in FIGS. 1 to 3 are denoted by the same reference numerals, and description thereof is omitted or simplified.

  4 to 14 are process cross-sectional views illustrating the method for fabricating the semiconductor device according to the present embodiment.

  In the present embodiment, an example in which the manufacturing method of the first embodiment is applied to a more specific method for manufacturing a semiconductor device will be described.

  First, an element isolation film 12 that defines an element region 14 is formed on a semiconductor substrate 10 that is a silicon substrate, for example, by a LOCOS (LOCal Oxidation of Silicon) method. The element isolation film 12 may be formed by an STI (Shallow Trench Isolation) method.

  Next, a gate electrode 18 formed on the semiconductor substrate 10 via a gate insulating film 16 on the element region 14 in the same manner as a normal MOS transistor manufacturing method, and in the semiconductor substrate 10 on both sides of the gate electrode 18 A MOS transistor 24 having the source / drain region 22 formed in the step is formed (FIG. 4A).

Next, for example, a silicon oxide film (SiO ₂ ) is formed on the semiconductor substrate 10 on which the MOS transistor 24 is formed by, eg, CVD.

  Next, the surface of the silicon oxide film is polished and flattened by, for example, a CMP (Chemical Mechanical Polishing) method, and an interlayer insulating film 26 made of a silicon oxide film and having a flattened surface is formed.

  Next, a silicon nitride film (SiN) of, eg, a 50 nm-thickness is deposited on the interlayer insulating film 26 by, eg, plasma CVD to form a silicon nitride stopper film 28. The stopper film 28 functions as a polishing stopper at the time of polishing by CMP and an etching stopper at the time of forming the wiring groove 46 in the interlayer insulating film 38 or the like in a process described later. As the stopper film 28, in addition to the silicon nitride film, a SiC: H film, a SiC: O: H film, a SiC: N film, or the like can be applied.

  Next, contact holes 30 reaching the source / drain regions 22 are formed in the stopper film 28 and the interlayer insulating film 26 by photolithography and dry etching (FIG. 4B).

  Next, a titanium nitride (TiN) film of, eg, a 50 nm-thickness is deposited on the entire surface by, eg, sputtering, to form a barrier metal 32 of the TiN film.

  Next, a tungsten (W) film 34 of, eg, a 1 μm-thickness is formed on the barrier metal 32 by, eg, CVD.

  Next, the tungsten film 34 and the barrier metal 32 are polished by, for example, a CMP method until the surface of the stopper film 28 is exposed, and a contact plug 35 that is embedded in the contact hole 30 and includes the adhesion layer 32 and the tungsten film 34 is formed. (FIG. 4 (c)).

  Next, an SiC: O: H film having a film thickness of, for example, 30 nm is deposited on the stopper film 28 in which the contact plug 35 is embedded by, for example, a plasma CVD method, thereby forming an insulating film 36 of an SiC: O: H film. The SiC: O: H film is a highly dense film in which oxygen and hydrogen are present in the SiC film, and functions as a barrier film that prevents diffusion of moisture and the like.

  Next, an interlayer insulating film 38 made of, for example, a porous silica material having a thickness of 160 nm is formed on the insulating film 36 (FIG. 5A). For the formation of the interlayer insulating film 38, various porous silica materials and film forming methods used for forming the silica-based insulating film 102 in the semiconductor device manufacturing method according to the first embodiment can be applied.

Next, a silicon oxide film (SiO ₂ ) of, eg, a 30 nm-thickness is deposited on the interlayer insulating film 38 by, eg, plasma CVD to form an insulating film 40 of the silicon oxide film (FIG. 5B).

  Next, a photoresist film 42 is formed on the insulating film 40 by photolithography in which an opening 44 is formed to expose a region where a first layer wiring 51 having a wiring width of 100 nm and a space of 100 nm is to be formed (FIG. 6). (A)).

Next, the insulating film 40, the interlayer insulating film 38, and the insulating film 36 are sequentially etched by dry etching using, for example, CF ₄ gas and CHF ₃ gas, using the photoresist film 42 as a mask and the stopper film 28 as a stopper. A wiring trench 46 for embedding the wiring 51 is formed in the film 40, the interlayer insulating film 38 and the insulating film 36 (FIG. 6B). By this dry etching, a damage layer 112 (X mark in the figure) in which Si—OH is generated is formed on the inner wall of the wiring groove 46.

  Next, the photoresist film 42 is removed by, for example, ashing using oxygen plasma. In the dry etching for forming the wiring groove 46, if a side wall deposit is formed on the inner wall of the wiring groove 46, it can be removed simultaneously in this ashing step.

Next, 3 cc of a silane compound such as hexamethyldisilazane is dropped, and spin coating is performed at 1000 rpm for 60 seconds, followed by baking at 120 ° C. for 60 seconds and 250 ° C. for 60 seconds on a hot plate. Perform in this order. As a result, Si—OH in the damaged layer introduced by dry etching when forming the wiring groove 46 becomes Si—CH ₃ , and the damaged layer 112 on the inner wall of the wiring groove 46 is repaired (in the drawing, the repair layer). 116) (FIG. 7A).

  Note that the silane compound used in the damage repair process of this embodiment and the process method using the same include various silanes used in the repair process of the damaged layer 112 of the insulating film 102 in the semiconductor device manufacturing method according to the first embodiment. A compound and a treatment method using the compound can be applied.

  Next, in a state where the substrate is heated to, for example, 400 ° C. in a nitrogen atmosphere, a high pressure mercury lamp (for example, UVL-7000H4-N manufactured by Ushio Inc.) is used, for example, ultraviolet rays having a wavelength of 200 to 600 nm are applied for, for example, 10 minutes. Irradiate (FIG. 7B). Thereby, Si—OH remaining after the damage repairing process by the silane compound is condensed to form a Si—O—Si bond, and moisture can be prevented from being adsorbed to the Si—OH.

  Various methods and conditions described in the first embodiment can be used for light irradiation used for the Si—OH condensation treatment. Further, as shown in the first embodiment, electron beam irradiation may be performed instead of light irradiation. Various methods and conditions shown in the first embodiment can be used for electron beam irradiation.

  Next, a tantalum nitride (TaN) film of, eg, a 10 nm-thickness is deposited on the entire surface by, eg, sputtering, to form a TaN film barrier metal 48. The barrier metal 48 is for preventing Cu from diffusing into the insulating film from the copper wiring formed in the process described later.

  Next, a Cu film of, eg, a 10 nm-thickness is deposited on the barrier metal 48 by, eg, sputtering, and a Cu film seed film (not shown) is formed.

  Next, a Cu film is deposited by, for example, electroplating using the seed film as a seed, and a Cu film 50 having a total film thickness of, for example, 600 nm combined with the seed layer is formed.

  Next, the Cu film 50 and the barrier metal 48 on the insulating film 40 are removed by polishing by CMP, and the wiring 51 including the barrier metal 48 and the Cu film 50 embedded in the wiring groove 46 is formed. Note that such a manufacturing process of the wiring 51 is referred to as a single damascene method.

  Next, an SiC: O: H film of, eg, a 30 nm-thickness is deposited on the entire surface by, eg, CVD, to form an insulating film 52 of SiC: O: H film (FIG. 8A). The insulating film 52 functions as a barrier film that prevents moisture diffusion and Cu diffusion from the Cu wiring.

  Next, an interlayer insulating film 54 made of a porous silica material is formed on the insulating film 52. As a method for forming the interlayer insulating film 54 made of a porous silica material, for example, a method similar to that of the above-described interlayer insulating film 38 can be applied. The film thickness of the interlayer insulating film 54 is, for example, 180 nm.

Next, an SiO ₂ (silicon oxide) film of, eg, a 30 nm-thickness is deposited on the interlayer insulating film 54 by, eg, plasma CVD to form an insulating film 56 of the SiO ₂ film (FIG. 8B).

  Next, an interlayer insulating film 58 made of a porous silica material is formed on the insulating film 56. As a method for forming the interlayer insulating film 58 made of a porous silica material, for example, a method similar to that of the above-described interlayer insulating film 38 can be applied. The film thickness of the interlayer insulating film 58 is 160 nm, for example.

Next, an SiO ₂ (silicon oxide) film of, eg, a 30 nm-thickness is deposited on the interlayer insulating film 58 by, eg, plasma CVD to form an insulating film 60 of the SiO ₂ film (FIG. 9).

  Next, a photoresist film 62 is formed on the insulating film 60 by photolithography. The photoresist film 62 has an opening 64 that exposes a region where a via hole is to be formed reaching the wiring 51.

Next, the insulating film 60, the interlayer insulating film 58, the insulating film 56, the interlayer insulating film 54, and the insulating film 52 are sequentially etched by dry etching using, for example, CF ₄ gas and CHF ₃ gas, using the photoresist film 62 as a mask. The via hole 66 reaching the wiring 51 is formed in the insulating film 60, the interlayer insulating film 58, the insulating film 56, the interlayer insulating film 54, and the insulating film 52 (FIG. 10). Each insulating film can be sequentially etched by appropriately changing the composition ratio of the etching gas, the pressure at the time of etching, and the like. By this dry etching, a damage layer 112 (X mark in the figure) in which Si—OH is generated is formed on the inner wall of the via hole 66.

  Next, the photoresist film 62 is removed by, for example, ashing. In the dry etching for forming the via hole 66, if a sidewall deposit is formed on the inner wall of the via hole 66, it can be removed simultaneously in this ashing process.

  Next, a photoresist film 68 is formed by photolithography on the insulating film 60 in which the via hole 66 is opened. The photoresist film 68 has an opening 70 that exposes a region where a second layer wiring 77b is to be formed.

Next, the insulating film 60, the interlayer insulating film 58, and the insulating film 56 are sequentially etched by dry etching using, for example, CF ₄ gas and CHF ₃ gas, using the photoresist film 68 as a mask, and the insulating film 60, the interlayer insulating film 58, and A wiring groove 72 for embedding the wiring 77b is formed in the insulating film 56 (FIG. 11). The wiring trench 72 is connected to the via hole 66. By this dry etching, a damage layer 112 (indicated by X in the figure) in which Si—OH is generated is formed on the inner wall of the wiring groove 72.

  Next, the photoresist film 68 is removed by, for example, ashing. In the case of dry etching when forming the wiring groove 72, if a sidewall deposit is formed on the inner wall of the wiring groove 72, it can be removed simultaneously in this ashing step.

Next, 3 cc of a silane compound such as hexamethyldisilazane is dropped, and spin coating is performed at 1000 rpm for 60 seconds, followed by baking at 120 ° C. for 60 seconds and 250 ° C. for 60 seconds on a hot plate. Perform in this order. Thereby, Si—OH in the damaged layer introduced by dry etching when forming the via hole 66 and the wiring groove 72 becomes Si—CH ₃ , and the damaged layer 112 on the inner wall of the via hole 66 and the wiring groove 72 is repaired. (Repair layer 116 in the figure) (FIG. 12).

  In addition, the silane compound used for the damage repair process of this embodiment and the treatment method using the same include various silane compounds used for the repair process of the damaged layer of the insulating film in the semiconductor device manufacturing method according to the first embodiment, and A processing method using the same can be applied.

  Next, in a state where the substrate is heated to, for example, 400 ° C. in a nitrogen atmosphere, a high pressure mercury lamp (for example, UVL-7000H4-N manufactured by Ushio Inc.) is used, for example, ultraviolet rays having a wavelength of 200 to 600 nm are applied for, for example, 10 minutes. Irradiate (FIG. 13). Thereby, Si—OH remaining after the damage repairing process by the silane compound is condensed to form a Si—O—Si bond, and moisture can be prevented from being adsorbed to the Si—OH.

  Various methods and conditions described in the first embodiment can be used for light irradiation used for the Si—OH condensation treatment. Further, as shown in the first embodiment, electron beam irradiation may be performed instead of light irradiation. Various methods and conditions shown in the first embodiment can be used for electron beam irradiation.

  Next, a TaN film of, eg, a 10 nm-thickness is deposited on the entire surface by, eg, sputtering, to form a barrier metal 74 of TaN film. The barrier metal 74 is for preventing Cu from diffusing into the insulating film from the copper wiring formed in the process described later.

  Next, a Cu film of, eg, a 10 nm-thickness is deposited on the barrier metal 74 by, eg, sputtering, and a Cu film seed film (not shown) is formed.

  Next, a Cu film is deposited by, for example, electroplating using the seed film as a seed, and a Cu film 76 having a total film thickness of, for example, 1400 nm combined with the seed layer is formed.

  Next, the Cu film 76 and the barrier metal 74 on the insulating film 60 are removed by polishing by CMP, and embedded in the via hole 66 and the contact plug 77a including the barrier metal 74 and the Cu film 76, and the wiring groove 72. The barrier metal 74 and the wiring 77b including the Cu film 76 are integrally and collectively formed. A manufacturing process in which the contact plug 77a and the wiring 77b are formed in a lump in this way is called a dual damascene method.

  Next, a SiC: O: H film of, eg, a 30 nm-thickness is deposited on the entire surface by, eg, CVD, to form an insulating film 78 of SiC: O: H film (FIG. 14). The insulating film 78 functions as a barrier film that prevents moisture diffusion and Cu diffusion from the Cu wiring.

  Thereafter, if necessary, the same steps as described above are repeated as appropriate to form a third-layer wiring (not shown) and the like, thereby completing the semiconductor device according to the present embodiment.

  As described above, according to the present embodiment, it is possible to recover the increase in the dielectric constant of the insulating film due to processing damage during dry etching and to prevent the increase in the dielectric constant due to being left in the atmosphere. Thereby, an insulating film having a low dielectric constant and high reliability can be obtained. Further, by applying this insulating film to, for example, an interlayer insulating film having a multilayer wiring structure, the response speed of the semiconductor device can be increased.

[Third Embodiment]
A method for fabricating a semiconductor device according to the third embodiment of the present invention will be described with reference to FIGS.

  FIG. 15 is a flowchart showing the semiconductor device manufacturing method according to the present embodiment. FIG. 16 is a process cross-sectional view showing the semiconductor device manufacturing method according to the present embodiment.

  As shown in FIG. 1, the semiconductor device manufacturing method according to the present embodiment includes a step of depositing a silica-based insulating film (step S31), a step of polishing the silica-based insulating film (step S32), and a dry process using a silane compound. There are a step of repairing etching damage (step S33, and a step of performing Si—OH condensation processing by light irradiation or electron beam irradiation (step S34).

  Hereinafter, each step will be described in detail with reference to FIG.

  First, a silica-based insulating film 202 is formed on the base substrate 200 (step S11) (FIG. 16A). Note that the base substrate 200 includes not only a semiconductor substrate itself such as a silicon substrate but also a semiconductor substrate on which an MIS transistor and other elements and one or more wiring layers are formed.

  As the silica-based insulating film 202, the same material as that of the silica-based insulating film 102 of the first embodiment can be applied. The film forming method is the same as that in the first embodiment.

  Next, the surface of the insulating film 202 is polished to a predetermined film thickness by, for example, a chemical mechanical polishing (CMP) method. At this time, a damaged layer 204 into which damage caused by polishing is introduced is formed on the surface of the polished insulating film 202 (FIG. 16B).

  The damage caused by polishing is mainly damage caused by an acid / alkali chemical used in CMP. The damage introduced into the insulating film by the acid / alkali chemical solution also generates Si—OH bonds as in the case of the dry etching of the first and second embodiments.

  Next, a treatment for repairing damage introduced when the insulating film 202 is polished is performed using a silane compound (step S33). By this treatment, the damage of the damage layer 204 on the surface of the insulating film 202 is repaired (the repair layer 206 in the figure) (FIG. 16C).

  Specifically, this treatment is for reacting Si—OH produced by damage during polishing with a silane compound. The treatment is not particularly limited as long as it is a treatment capable of reacting Si-OH with a silane compound, and preferably a spin coating method, a vapor method in which the silane compound is treated as described above under normal pressure or vacuum, and the like. Can be applied. Among these, the vapor method which is not easily affected by the surface tension is more preferable.

  In the vapor method, it is desirable to heat the substrate temperature to 50 to 350 ° C. in order to diffuse the silane compound into the insulating film 202 and strengthen the repaired portion. In the spin coating method, the treatment is performed at room temperature by a spin coater, but a baking treatment may be performed after the spin coating in order to strengthen the repaired portion. In this case, it is desirable to perform baking at a single temperature or a plurality of temperatures in the range of 50 to 350 ° C.

  It is desirable that the treatment temperature is appropriately selected in the temperature range of 50 to 350 ° C. according to the type of the silane compound. The upper limit of the treatment temperature is mainly defined by the boiling point of the silane compound and is set to a temperature equal to or lower than the boiling point of the silane compound. The lower limit of the treatment temperature is set to 50 ° C. because the effect of repairing damage by the silane compound cannot be sufficiently obtained at a temperature lower than that.

  The silane compound applicable to the damage repair treatment is not particularly limited as long as it contains a functional group that reacts with Si-OH generated by damage during dry etching. For example, dimethyldisilazane, tetramethyldisilazane Silazane compounds such as hexamethyldisilazane, silylamide compounds such as bis (trimethylsilyl) acetamide and bis (triethylsilyl) acetamide, trimethoxysilane, triethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethylmethoxysilane, dimethyl Ethoxysilane, trimethylmethoxysilane, trimethylethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, diethylmethoxysilane, diethylethoxysilane, triethylmethoxysilane , Triethylethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, dipropylmethoxysilane, dipropylethoxysilane, tripropylmethoxysilane, tripropylethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, diphenylmethoxysilane, Alkoxysilane compounds such as diphenylethoxysilane, triphenylmethoxysilane, triphenylethoxysilane, phenylmethylmethoxysilane, phenylmethylethoxysilane, dimethylphenylmethoxysilane, dimethylphenylethoxysilane, diphenylmethylmethoxysilane, diphenylmethylethoxysilane, Acetoxysilane, triethoxysilane, methyltriethoxysilane, dimethylacetoxysila , Trimethylacetoxysilane, ethyltriethoxysilane, diethylacetoxysilane, triethylacetoxysilane, dipropylacetoxysilane, tripropylacetoxysilane, phenyltriacetoxysilane, diphenylacetoxysilane, triphenylacetoxysilane, phenylmethylacetoxysilane, dimethylphenylacetoxy Acetoxysilane compounds such as silane and diphenylmethylacetoxysilane can be used.

By the damage repair process described above, Si—OH in the damage layer 204 becomes Si—CH ₃ , and hydrophobicity can be increased. However, a large molecular mass of the silane compound becomes a steric hindrance, and it is difficult to convert all Si—OH into Si—CH ₃ . As a result, if the substrate is left in the air as it is, moisture is gradually adsorbed to Si—OH, causing an increase in the dielectric constant of the insulating film 202.

  Therefore, in the method for manufacturing the semiconductor device according to the present embodiment, after the damage repair process using the silane compound, the remaining Si—OH is condensed (dehydrated) to form Si—O—Si bonds, thereby forming Si The moisture is prevented from being adsorbed to -OH (step S15). The Si—OH condensation treatment can be realized by performing light irradiation or electron beam irradiation treatment while heating the substrate to 30 to 400 ° C. (FIG. 16D).

  The condensation treatment by light irradiation is not particularly limited as long as light having a wavelength of 170 to 700 nm can be irradiated. For example, an excimer lamp, a mercury lamp, and a metal can be a ride lamp. The substrate temperature during light irradiation is preferably 30 to 400 ° C.

  The atmosphere preferably has an oxygen concentration of 150 ppm or less, and nitrogen, helium (He), argon, a plurality of these gases, or a vacuum can be used. When performing in vacuum (under reduced pressure), nitrogen, helium, argon, or a plurality of these gases are introduced while controlling the pressure in the vacuum chamber to a predetermined pressure using a mass flow meter or the like. You may do it.

  In the condensation treatment by electron beam irradiation, it is desirable to irradiate an electron beam having an acceleration voltage of 1 to 15 kV in a vacuum. This is because if the acceleration voltage is less than 1 kV, a sufficient effect cannot be expected, and if the acceleration voltage is higher than 15 kV, the insulating film may be damaged.

  It is desirable that the treatment temperature at the time of light irradiation or electron beam irradiation is appropriately selected in the temperature range of 30 to 400 ° C. according to the type of the silica-based insulating film. The upper limit of the processing temperature is mainly defined by the heat resistant temperature of the silica-based insulating film forming the insulating film, and is set to a temperature lower than the heat resistant temperature of the silica-based insulating film. The lower limit of the treatment temperature is 30 ° C. because the condensation reaction does not sufficiently occur at a temperature lower than that.

  Thus, by performing the Si—OH condensation treatment after the damage repair treatment with the silane compound, the hygroscopicity of the insulating film can be significantly reduced. Thereby, the adsorption | suction of the water | moisture content accompanying leaving to air | atmosphere is reduced significantly, and it can prevent effectively that a dielectric constant raises by adsorption | suction of a water | moisture content.

  As described above, according to the present embodiment, it is possible to recover the increase in the dielectric constant of the insulating film due to the damage introduced by the polishing, and to prevent the increase in the dielectric constant due to being left in the atmosphere.

[Fourth Embodiment]
A method for fabricating a semiconductor device according to the fourth embodiment of the present invention will be explained with reference to FIGS. The same components as those in the semiconductor device manufacturing method according to the first to third embodiments shown in FIGS. 1 to 16 are denoted by the same reference numerals, and the description thereof is omitted or simplified.

  17 to 21 are process cross-sectional views illustrating the method for fabricating the semiconductor device according to the present embodiment.

  In the present embodiment, an example in which the manufacturing method of the third embodiment is applied to the manufacturing method of the semiconductor device according to the second embodiment will be described.

  First, in the same way as in the method for manufacturing the semiconductor device according to the second embodiment shown in FIGS. 4A to 5B, for example, the element isolation film 12, the MOS transistor 24, and the interlayer insulating film 26 are formed on the semiconductor substrate 10. Then, a stopper film, contact plug 35, insulating film 36, interlayer insulating film 38 and insulating film 40 are formed (FIG. 17A).

  Next, for example, in the same way as in the method of manufacturing the semiconductor device according to the second embodiment shown in FIGS. 6A to 6B, the wiring 51 is embedded in the insulating film 40, the interlayer insulating film and the insulating film 36. A wiring groove 46 is formed.

  Next, for example, in the same way as in the method of manufacturing the semiconductor device according to the second embodiment shown in FIGS. 7A to 7B, the treatment with the silane compound and the ultraviolet irradiation are performed, and the dry process for forming the wiring groove 46 is performed. The damaged layer introduced by etching is repaired (repair layer 116 in the figure) (FIG. 17B).

  Next, a titanium nitride (TaN) film of, eg, a 50 nm-thickness is deposited on the entire surface by, eg, sputtering, to form a TaN film barrier metal 48.

  Next, a Cu film of, eg, a 10 nm-thickness is deposited on the barrier metal 48 by, eg, sputtering, and a Cu film seed film (not shown) is formed.

  Next, a Cu film is deposited by, for example, electroplating using the seed film as a seed, and a Cu film 50 having a total film thickness of, for example, 600 nm combined with the seed layer is formed.

  Next, the Cu film 50 and the barrier metal 48 on the insulating film 40 are removed by polishing by CMP, and the wiring 51 including the barrier metal 48 and the Cu film 50 embedded in the wiring groove 46 is formed. It is desirable that the slurry used for CMP is appropriately selected according to the material of the wiring 51, the material of the insulating film 40, and the like. By this polishing process, a damaged layer in which Si—OH is generated is formed in the insulating film 40.

  In the step of forming the wiring 51, an acid / alkali chemical used for polishing acts on the insulating film 40 to form Si—OH bonds in the film. In the present specification, a process that exerts some physical / chemical action on the insulating film is expressed as a process of processing the insulating film. That is, the step of processing the insulating film includes a step of patterning the insulating film by dry etching or the like, a step of removing the conductive film on the insulating film by polishing, a step of removing a part of the insulating film by polishing, and the like. .

Next, 3 cc of a silane compound such as hexamethyldisilazane is dropped, and spin coating is performed at 1000 rpm for 60 seconds. Perform in this order. As a result, Si—OH in the insulating film 40 introduced by polishing when forming the wiring 51 becomes Si—CH ₃ , and damage to the insulating film 40 is repaired.

  The silane compound used in the damage repair process of this embodiment and the process method using the same include various silanes used in the repair process of the damaged layer 204 of the insulating film 202 in the semiconductor device manufacturing method according to the third embodiment. A compound and a treatment method using the compound can be applied.

  Next, in a state where the substrate is heated to, for example, 400 ° C. in a nitrogen atmosphere, a high pressure mercury lamp (for example, UVL-7000H4-N manufactured by Ushio Inc.) is used, for example, ultraviolet rays having a wavelength of 200 to 600 nm are applied for, for example, 10 minutes. Irradiate (FIG. 18A). Thereby, Si—OH remaining after the damage repairing process by the silane compound is condensed to form a Si—O—Si bond, and moisture can be prevented from being adsorbed to the Si—OH.

  Various methods and conditions shown in the third embodiment can be used for light irradiation used for the Si—OH condensation treatment. Further, as shown in the third embodiment, electron beam irradiation may be performed instead of light irradiation. Various methods and conditions shown in the third embodiment can be used for electron beam irradiation.

  Next, on the insulating film 40 in which the wiring 51 is embedded, the insulating film 52, the interlayer insulating film 54, and the insulating film are formed in the same manner as in, for example, the semiconductor device manufacturing method according to the second embodiment shown in FIGS. A film 60 is formed (FIG. 18B). In this embodiment, a three-layer structure of insulating film 60 / interlayer insulating film 54 / insulating film 52 is used. However, a structure including an insulating film 56 for an etching stopper may be used as in the second embodiment. . In this embodiment, as the interlayer insulating film 54, for example, a porous silica film having a film thickness of 180 nm can be used.

  Next, for example, in the same manner as in the method of manufacturing the semiconductor device according to the second embodiment shown in FIGS. 10 to 11, via holes 66 reaching the wirings 51 are formed in the insulating film 52 and the interlayer insulating film 54. A wiring groove 72 for embedding the wiring 77b is formed.

  Next, for example, in the same way as in the method of manufacturing the semiconductor device according to the second embodiment shown in FIGS. 12 to 13, treatment with a silane compound and ultraviolet irradiation are performed and dry etching is performed when forming the via hole 66 and the wiring groove 46. The damaged layer is repaired (repair layer 116 in the figure) (FIG. 19).

  Next, a TaN film of, eg, a 10 nm-thickness is deposited on the entire surface by, eg, sputtering, to form a barrier metal 74 of TaN film.

  Next, a Cu film of, eg, a 10 nm-thickness is deposited on the barrier metal 74 by, eg, sputtering, and a Cu film seed film (not shown) is formed.

  Next, a Cu film is deposited by, for example, electroplating using the seed film as a seed, and a Cu film 76 having a total film thickness of, for example, 1400 nm combined with the seed layer is formed.

  Next, the Cu film 76 and the barrier metal 74 on the insulating film 60 are removed by polishing by CMP, and embedded in the via hole 66 and the contact plug 77a including the barrier metal 74 and the Cu film 76, and the wiring groove 72. The barrier metal 74 and the wiring 77b including the Cu film 76 are integrally and collectively formed. It is desirable that the slurry used for CMP is appropriately selected according to the material of the contact plug 77a and the wiring 77b, the material of the insulating film 60, and the like. By this polishing process, a damaged layer in which Si—OH is generated is formed in the insulating film 60.

Next, 3 cc of a silane compound such as hexamethyldisilazane is dropped, and spin coating is performed at 1000 rpm for 60 seconds, followed by baking at 120 ° C. for 60 seconds and 250 ° C. for 60 seconds on a hot plate. Perform in this order. Thus, Si—OH in the insulating film 60 introduced by polishing when forming the contact plug 77a and the wiring 77b becomes Si—CH ₃ , and damage to the insulating film 60 is repaired.

  The silane compound used in the damage repair process of this embodiment and the process method using the same include various silanes used in the repair process of the damaged layer 204 of the insulating film 202 in the semiconductor device manufacturing method according to the third embodiment. A compound and a treatment method using the compound can be applied.

  Next, in a state where the substrate is heated to, for example, 400 ° C. in a nitrogen atmosphere, a high pressure mercury lamp (for example, UVL-7000H4-N manufactured by Ushio Inc.) is used, for example, ultraviolet rays having a wavelength of 200 to 600 nm are applied for, for example, 10 minutes. Irradiate (FIG. 20). Thereby, Si—OH remaining after the damage repairing process by the silane compound is condensed to form a Si—O—Si bond, and moisture can be prevented from being adsorbed to the Si—OH.

  Various methods and conditions shown in the third embodiment can be used for light irradiation used for the Si—OH condensation treatment. Further, as shown in the third embodiment, electron beam irradiation may be performed instead of light irradiation. Various methods and conditions shown in the third embodiment can be used for electron beam irradiation.

  Next, a SiC: O: H film of, eg, a 30 nm-thickness is deposited on the entire surface by, eg, CVD, to form an insulating film 78 of SiC: O: H film (FIG. 21).

  Thereafter, if necessary, the same steps as described above are repeated as appropriate to form a third-layer wiring (not shown) and the like, thereby completing the semiconductor device according to the present embodiment.

  Thus, according to the present embodiment, it is possible to recover the increase in the dielectric constant of the insulating film due to processing damage when processing the insulating film, and to prevent the increase in the dielectric constant due to being left in the atmosphere. As a result, an insulating film having a low dielectric constant and high reliability can be obtained. By applying this insulating film to, for example, an interlayer insulating film having a multilayer wiring structure, the response speed of the semiconductor device can be increased. .

[Fifth Embodiment]
A method for fabricating a semiconductor device according to the fifth embodiment of the present invention will be explained with reference to FIGS. The same components as those in the method of manufacturing the semiconductor device according to the first to fourth embodiments shown in FIGS. 1 to 21 are denoted by the same reference numerals, and description thereof will be omitted or simplified.

  22 to 26 are process cross-sectional views illustrating the method for fabricating the semiconductor device according to the present embodiment.

  In the present embodiment, another example in which the manufacturing method of the third embodiment is applied to the manufacturing method of the semiconductor device according to the second embodiment will be described.

  First, in the same way as in the method for manufacturing the semiconductor device according to the second embodiment shown in FIGS. 4A to 5B, for example, the element isolation film 12, the MOS transistor 24, and the interlayer insulating film 26 are formed on the semiconductor substrate 10. Then, a stopper film, contact plug 35, insulating film 36, interlayer insulating film 38 and insulating film 40 are formed (FIG. 22A).

  Next, for example, in the same way as in the method of manufacturing the semiconductor device according to the second embodiment shown in FIGS. 6A to 6B, the wiring 51 is embedded in the insulating film 40, the interlayer insulating film and the insulating film 36. A wiring groove 46 is formed.

  Next, for example, in the same way as in the method of manufacturing the semiconductor device according to the second embodiment shown in FIGS. 7A to 7B, the treatment with the silane compound and the ultraviolet irradiation are performed, and the dry process for forming the wiring groove 46 is performed. The damaged layer introduced by etching is repaired (repair layer 116 in the figure) (FIG. 22B).

  Next, a tantalum nitride (TaN) film of, eg, a 10 nm-thickness is deposited on the entire surface by, eg, sputtering, to form a TaN film barrier metal 48.

  Next, a Cu film of, eg, a 10 nm-thickness is deposited on the barrier metal 48 by, eg, sputtering, and a Cu film seed film (not shown) is formed.

  Next, a Cu film is deposited by, for example, electroplating using the seed film as a seed, and a Cu film 50 having a total film thickness of, for example, 600 nm combined with the seed layer is formed.

  Next, the Cu film 50, the barrier metal 48, and the insulating film 40 on the interlayer insulating film 38 are removed by polishing by CMP, and a wiring 51 that is embedded in the wiring trench 46 and includes the barrier metal 48 and the Cu film 50 is formed. .

  In the present embodiment, the insulating film 40 is also removed in the polishing step when forming the wiring 51. The insulating film 40 is used as a hard mask when forming the wiring trench 46, but is generally formed of a material having a higher dielectric constant than the material of the interlayer insulating film 38. Therefore, in this embodiment, from the viewpoint of reducing the dielectric constant of the interlayer insulating film, the insulating film 40 is also removed in the polishing step when forming the wiring 51. When the insulating film 40 is removed by polishing, a damaged layer in which Si—OH is generated is formed in the lower interlayer insulating film 38 by this polishing process.

  Next, for example, in the same way as in the method of manufacturing the semiconductor device according to the fourth embodiment shown in FIG. 18A, the treatment with the silane compound and the ultraviolet irradiation are performed, and the wiring 51 is formed by polishing in the interlayer insulating film 38. The introduced damage is repaired (FIG. 23 (a)).

  When the insulating film 40 is removed by polishing, damage may be introduced into the lower interlayer insulating film 38 and the dielectric constant of the interlayer insulating film 38 may increase. However, the damage introduced into the interlayer insulating film 38 is repaired by performing the above-described damage repairing process, and an increase in the dielectric constant of the interlayer insulating film 38 can be prevented. Further, by removing the insulating film 40, the dielectric constant of the interlayer insulating film can be further reduced.

  Next, the insulating film 52, the interlayer insulating film 54, and the insulating film 60 are formed on the interlayer insulating film 38 in which the wiring 51 is embedded, for example, in the same manner as in the method of manufacturing the semiconductor device according to the third embodiment shown in FIG. Is formed (FIG. 23B). In this embodiment, a three-layer structure of insulating film 60 / interlayer insulating film 54 / insulating film 52 is used. However, a structure including an insulating film 56 for an etching stopper may be used as in the second embodiment. .

  Next, for example, in the same manner as in the method of manufacturing the semiconductor device according to the second embodiment shown in FIGS. 10 to 11, via holes 66 reaching the wirings 51 are formed in the insulating film 52 and the interlayer insulating film 54. A wiring groove 72 for embedding the wiring 77b is formed.

  Next, for example, in the same way as in the method of manufacturing the semiconductor device according to the second embodiment shown in FIGS. 12 to 13, treatment with a silane compound and ultraviolet irradiation are performed and dry etching is performed when forming the via hole 66 and the wiring groove 46. The damaged layer is repaired (repair layer 116 in the figure) (FIG. 24).

  Next, a TaN film of, eg, a 10 nm-thickness is deposited on the entire surface by, eg, sputtering, to form a barrier metal 74 of TaN film.

  Next, a Cu film of, eg, a 10 nm-thickness is deposited on the barrier metal 74 by, eg, sputtering, and a Cu film seed film (not shown) is formed.

  Next, a Cu film is deposited by, for example, electroplating using the seed film as a seed, and a Cu film 76 having a total film thickness of, for example, 1400 nm combined with the seed layer is formed.

  Next, the Cu film 76 and the barrier metal 74 on the insulating film 60 are removed by polishing by CMP, and embedded in the via hole 66 and the contact plug 77a including the barrier metal 74 and the Cu film 76, and the wiring groove 72. The barrier metal 74 and the wiring 77b including the Cu film 76 are integrally and collectively formed.

  In the present embodiment, the insulating film 60 is also removed in the polishing step when forming the contact plug 77a and the wiring 77b. The insulating film 60 is used as a hard mask when forming the via hole 66 and the wiring groove 46, and is generally formed of a material having a higher dielectric constant than the material of the interlayer insulating film 54. Therefore, in this embodiment, from the viewpoint of reducing the dielectric constant of the interlayer insulating film, the insulating film 60 is also removed in the polishing step when forming the contact plug 77a and the wiring 77b. When the insulating film 60 is removed by polishing, a damaged layer in which Si—OH is generated is formed in the lower interlayer insulating film 54 by this polishing process.

  Next, for example, in the same manner as in the method of manufacturing the semiconductor device according to the fourth embodiment shown in FIG. 19, the treatment with the silane compound and the ultraviolet irradiation are performed to polish the interlayer insulating film 54 by polishing when forming the contact plug 77a and the wiring 77b. The damage introduced in is repaired (FIG. 25).

  When the insulating film 60 is removed by polishing, damage may be introduced into the lower interlayer insulating film 54 and the dielectric constant of the interlayer insulating film 54 may increase. However, the damage introduced into the interlayer insulating film 54 is repaired by performing the above-described damage repairing process, and the dielectric constant of the interlayer insulating film 54 can be prevented from increasing. Further, by removing the insulating film 60, the dielectric constant of the interlayer insulating film can be further reduced.

  Next, a SiC: O: H film of, eg, a 30 nm-thickness is deposited on the entire surface by, eg, CVD, to form an insulating film 78 of SiC: O: H film (FIG. 26).

  Thereafter, if necessary, the same steps as described above are repeated as appropriate to form a third-layer wiring (not shown) and the like, thereby completing the semiconductor device according to the present embodiment.

  Thus, according to the present embodiment, it is possible to recover the increase in the dielectric constant of the insulating film due to processing damage when processing the insulating film, and to prevent the increase in the dielectric constant due to being left in the atmosphere. As a result, an insulating film having a low dielectric constant and high reliability can be obtained. By applying this insulating film to, for example, an interlayer insulating film having a multilayer wiring structure, the response speed of the semiconductor device can be increased. .

[Modified Embodiment]
The present invention is not limited to the structure of the semiconductor device and the manufacturing method thereof disclosed in the above embodiments, and can be widely applied to the manufacture of semiconductor devices having a silica-based insulating film. The film thickness and constituent materials of each layer forming the semiconductor device can be changed as appropriate.

[Example 1]
Tetraethoxysilane 20.8 g (0.1 mol), methyltriethoxysilane 17.8 g (0.1 mol), glycidoxypropyltrimethoxysilane 23.6 g (0.1 mol), methyl isobutyl ketone 39.6 g, 200 ml The reaction vessel was charged, and 16.2 g (0.9 mol) of 1% tetramethylammonium hydroxide aqueous solution was added dropwise over 10 minutes. After completion of the addition, an aging reaction was performed for 2 hours.

  Next, 5 g of magnesium sulfate was added to remove excess water, and then the ethanol produced by the aging reaction was removed with a rotary evaporator until the reaction solution reached 50 ml. 20 ml of methyl isobutyl ketone was added to the obtained reaction solution to prepare a porous silica precursor coating solution.

The prepared porous silica precursor coating solution is spin-coated on a low resistance substrate, prebaked at 250 ° C. for 3 minutes, and then calculated from the absorption intensity of Si—OH near 950 cm ⁻¹ using FT-IR. As a result, the crosslinking rate was 75%.

  Next, the porous silica precursor coating solution thus prepared was applied onto the silicon substrate 300 by spin coating so that the film thickness was 400 nm.

  Next, the porous silica precursor coating solution coated on the silicon substrate 200 was pre-baked at 250 ° C. for 3 minutes.

  Next, the pre-baked porous silica precursor coating solution was cured in an electric furnace in a nitrogen atmosphere at 400 ° C. for 30 minutes to form a silica-based porous insulating film 302 (FIG. 27A).

Next, the silica-based porous insulating film 302 formed in this way is mixed with CHF ₃ / CF ₄ as an etching gas using an RIE etcher, with a CHF ₃ flow rate of 50 sccm, a CF ₄ flow rate of 100 sccm, and a chamber pressure of Dry etching was performed at 50 mTorr, power of 200 W, and a film thickness of 200 nm. As a result, the silica-based porous insulating film 302 is reduced in film thickness, and a damaged layer 304 is formed on the surface (FIG. 27B).

  Next, 3 cc of hexamethyldisilazane was dropped on the silica-based porous insulating film 302 subjected to dry etching, and spin coating was performed under conditions of 1000 rpm and 60 seconds.

  Next, a baking process at 120 ° C. for 60 seconds and a baking process at 250 ° C. for 60 seconds were performed in this order on a hot plate. As a result, the damaged layer 304 is repaired, and a repair layer 306 is formed on the surface of the silica-based porous insulating film 302 (FIG. 27C).

  Next, with the substrate heated to 400 ° C. in a nitrogen atmosphere, the silica-based porous insulating film was irradiated with ultraviolet rays having a wavelength of 200 to 600 nm for 10 minutes with a high-pressure mercury lamp (manufactured by Ushio Inc., UVL-7000H4-N). (FIG. 27 (d)).

  Table 1 summarizes the results of calculating the dielectric constant of the silica-based porous insulating film 302 after each step and after being left in the atmosphere for one week from the capacity measured with a mercury probe.

  As shown in Table 1, the dielectric constant immediately after the formation of the silica-based porous insulating film 302 was 2.24. By subjecting this film to dry etching, the dielectric constant increased to 2.86 due to the formation of the damaged layer 304. Thereafter, by performing a recovery treatment with a silane compound, the dielectric constant recovered to 2.36, but it did not return to the value immediately after film formation. However, the dielectric constant was recovered to 2.26, which is close to the value immediately after the film formation, by performing further ultraviolet irradiation after the recovery treatment with the silane compound. Further, even after being left in the atmosphere for 1 week, the dielectric constant was 2.25, and the low value was maintained immediately after film formation.

[Example 2]
An evaluation sample was prepared in the same manner as in Example 1 except that electron beam irradiation was performed instead of light irradiation in the step of FIG. The electron beam irradiation was performed by heating the substrate to 400 ° C. in a vacuum and irradiating it with an acceleration voltage of 10 kV for 1 minute.

  Table 1 summarizes the results of calculating the dielectric constant of the silica-based porous insulating film after each step and after standing for 1 week in the atmosphere from the capacity measured with a mercury probe.

  As shown in Table 1, the dielectric constant immediately after the formation of the silica-based porous insulating film was 2.24. By subjecting this film to dry etching, the dielectric constant increased to 2.86 due to the formation of the damaged layer. Thereafter, by performing a recovery treatment with a silane compound, the dielectric constant recovered to 2.36, but it did not return to the value immediately after film formation. However, by performing further electron beam irradiation after the recovery treatment with the silane compound, the dielectric constant recovered to 2.28, which is close to the value immediately after film formation. Further, even after being left in the atmosphere for 1 week, the dielectric constant was 2.26, and the low value was maintained immediately after film formation.

[Comparative Example 1]
An evaluation sample was prepared in the same manner as in Example 1 and Example 2 except that light irradiation and electron beam irradiation were not performed in the step of FIG.

  Table 1 summarizes the results of calculating the dielectric constant of the silica-based porous insulating film after each step and after standing for 1 week in the atmosphere from the capacity measured with a mercury probe.

  As shown in Table 1, the dielectric constant immediately after the formation of the silica-based porous insulating film was 2.24. By subjecting this film to dry etching, the dielectric constant increased to 2.86 due to the formation of the damaged layer. Thereafter, by performing a recovery treatment with a silane compound, the dielectric constant recovered to 2.36, but it did not return to the value immediately after film formation. Then, when it was left in the atmosphere for 1 week without performing light irradiation and electron beam irradiation, the dielectric constant increased to 2.52.

[Example 3]
Up to the third wiring layer was formed by the semiconductor device manufacturing method according to the second embodiment. The third wiring layer was formed under the same process conditions as the second wiring layer.

  The yield of 1 million continuous vias was measured using the multilayer wiring of the prototype semiconductor device and found to be 91%. The effective dielectric constant of the interlayer insulating film was measured by interlayer capacitance and found to be 2.60. Further, when the wiring resistance was measured after leaving at 200 ° C. for 1000 hours, no increase in resistance was observed.

[Example 4]
A semiconductor device was manufactured by the same process as in Example 3 except that the ultraviolet irradiation after the damage repair treatment with the silane compound was performed in a helium atmosphere. Specifically, ultraviolet irradiation after damage repairing treatment was performed using a high-pressure mercury lamp (UVL-7000H4-N, manufactured by Ushio Electric Co., Ltd.) in a state where the substrate was heated to 400 ° C. in a helium atmosphere, and the wavelength was 200 to 200. This was performed by irradiating 600 nm ultraviolet rays for 10 minutes.

  When the yield of 1 million continuous vias was measured using the multilayer wiring of the prototype semiconductor device, it was 94%. The effective dielectric constant of the interlayer insulating film was measured by interlayer capacitance and found to be 2.58. Further, when the wiring resistance was measured after leaving at 200 ° C. for 1000 hours, no increase in resistance was observed.

[Example 5]
A semiconductor device was manufactured by the same process as in Example 3 except that the ultraviolet irradiation after the damage repair treatment with the silane compound was performed in an argon atmosphere. Specifically, ultraviolet irradiation after damage repairing treatment was performed using a high-pressure mercury lamp (UVL-7000H4-N manufactured by Ushio Electric Co., Ltd.) in a state where the substrate was heated to 400 ° C. in an argon atmosphere, and the wavelength was 200 to 200 ° C. This was performed by irradiating 600 nm ultraviolet rays for 10 minutes.

  The yield of 1 million continuous vias was measured using the multilayer wiring of the prototype semiconductor device and found to be 93%. The effective dielectric constant of the interlayer insulating film was measured by interlayer capacitance and found to be 2.61. Further, when the wiring resistance was measured after leaving at 200 ° C. for 1000 hours, no increase in resistance was observed.

[Example 6]
A semiconductor device was manufactured by the same process as in Example 3 except that the ultraviolet irradiation after the damage repair treatment with the silane compound was performed in vacuum. Specifically, UV irradiation after damage repair processing is performed using a high-pressure mercury lamp (UVL-7000H4-N, manufactured by USHIO INC.) In a state where the substrate is heated to 400 ° C. in a vacuum, and the wavelength is 200 to 600 nm. The ultraviolet rays were irradiated for 10 minutes.

  The yield of 1 million continuous vias was measured using the multilayer wiring of the prototype semiconductor device and found to be 96%. The effective dielectric constant of the interlayer insulating film was measured by interlayer capacitance and found to be 2.52. Further, when the wiring resistance was measured after leaving at 200 ° C. for 1000 hours, no increase in resistance was observed.

[Example 7]
A semiconductor device was manufactured in the same process as in Example 3 except that electron beam irradiation was performed instead of ultraviolet irradiation after the damage repair treatment with the silane compound. The electron beam irradiation was performed by irradiating the substrate at 400 ° C. in vacuum for 1 minute at an acceleration voltage of 10 kV.

  The yield of 1 million continuous vias was measured using the multilayer wiring of the prototype semiconductor device and found to be 90%. The effective dielectric constant of the interlayer insulating film was measured by interlayer capacitance and found to be 2.63. Further, when the wiring resistance was measured after leaving at 200 ° C. for 1000 hours, no increase in resistance was observed.

[Comparative Example 2]
In the process of Example 3, a semiconductor device was manufactured without performing damage repair treatment with a silane compound, light irradiation, and electron beam irradiation treatment.

  The yield of 1 million continuous vias was measured using the multilayer wiring of the prototype semiconductor device and found to be 72%. The effective dielectric constant of the interlayer insulating film was measured by interlayer capacitance and found to be 2.96. Further, when the wiring resistance was measured after leaving at 200 ° C. for 1000 hours, an increase in resistance was observed in 45% of the number of vias.

[Comparative Example 3]
In the process of Example 3, only the damage repair process with the silane compound was performed, and the semiconductor device was manufactured without performing the light irradiation and the electron beam irradiation process.

  When the yield of 1 million continuous vias was measured using the multilayer wiring of the prototype semiconductor device, it was 81%. The effective dielectric constant of the interlayer insulating film was measured by interlayer capacitance and found to be 2.82. Further, when the wiring resistance was measured after leaving at a high temperature of 200 ° C. for 1000 hours, an increase in resistance was observed in 18% of the number of vias.

[Example 8]
Tetraethoxysilane 20.8 g (0.1 mol), methyltriethoxysilane 17.8 g (0.1 mol), glycidoxypropyltrimethoxysilane 23.6 g (0.1 mol), methyl isobutyl ketone 39.6 g, 200 ml The reaction vessel was charged, and 16.2 g (0.9 mol) of 1% tetramethylammonium hydroxide aqueous solution was added dropwise over 10 minutes. After completion of the addition, an aging reaction was performed for 2 hours.

  Next, 5 g of magnesium sulfate was added to remove excess water, and then the ethanol produced by the aging reaction was removed with a rotary evaporator until the reaction solution reached 50 ml. 20 ml of methyl isobutyl ketone was added to the resulting reaction solution to prepare a porous silica precursor coating solution for a wiring separation layer.

The prepared porous silica precursor coating solution is spin-coated on a low resistance substrate, prebaked at 250 ° C. for 3 minutes, and then calculated from the absorption intensity of Si—OH near 950 cm ⁻¹ using FT-IR. As a result, the crosslinking rate was 75%.

  Next, the porous silica precursor coating solution thus prepared was applied onto a silicon substrate as the base substrate 200 by spin coating so that the film thickness was 400 nm.

  Next, the porous silica precursor coating solution coated on the base substrate 200 was pre-baked at 250 ° C. for 3 minutes.

  Next, the pre-baked porous silica precursor coating solution was cured in an electric furnace in a nitrogen atmosphere at 400 ° C. for 30 minutes to form a silica-based porous insulating film 202 (see FIG. 16A). .

  Next, the silica-based porous insulating film 202 formed in this way was polished by a chemical mechanical polishing (CMP) apparatus. As a result, the silica-based porous insulating film 202 is reduced in thickness, and a damaged layer 204 is formed on the surface (see FIG. 16B).

  Next, the surface of the polished silica-based porous insulating film 202 was washed with a 0.5% aqueous hydrofluoric acid solution.

  Next, 3 cc of hexamethyldisilazane was dropped onto the polished silica-based porous insulating film 202, and spin coating was performed at 1000 rpm for 60 seconds.

  Next, a baking process at 120 ° C. for 60 seconds and a baking process at 250 ° C. for 60 seconds were performed in this order on a hot plate. As a result, the damaged layer 204 is repaired, and a repair layer 206 is formed on the surface of the silica-based porous insulating film 202 (see FIG. 16C).

  Next, with the substrate heated to 400 ° C. in a nitrogen atmosphere, the silica-based porous insulating film was irradiated with ultraviolet rays having a wavelength of 200 to 600 nm for 10 minutes with a high-pressure mercury lamp (manufactured by Ushio Inc., UVL-7000H4-N). (FIG. 15D).

  Table 2 summarizes the results of calculating the dielectric constant of the silica-based porous insulating film 202 after each step and after standing for 1 week in the atmosphere from the capacity measured with a mercury probe.

  As shown in Table 2, the dielectric constant immediately after the formation of the silica-based porous insulating film 202 was 2.24. By polishing this film, the dielectric constant increased to 3.12. Thereafter, by performing a recovery treatment with a silane compound, the dielectric constant recovered to 2.39, but it did not return to the value immediately after film formation. However, the dielectric constant was recovered to 2.25, which is close to the value immediately after the film formation, by performing ultraviolet irradiation after the recovery treatment with the silane compound. Further, even after being left in the atmosphere for 1 week, the dielectric constant was 2.25, and the low value was maintained immediately after film formation.

[Example 9]
An evaluation sample was prepared in the same manner as in Example 8 except that electron beam irradiation was performed instead of light irradiation in the step of FIG. The electron beam irradiation was performed by heating the substrate to 400 ° C. in a vacuum and irradiating it with an acceleration voltage of 10 kV for 1 minute.

  Table 2 summarizes the results of calculating the dielectric constant of the silica-based porous insulating film after each step and after standing for 1 week in the atmosphere from the capacity measured with a mercury probe.

  As shown in Table 2, the dielectric constant immediately after the formation of the silica-based porous insulating film 202 was 2.24. By polishing this film, the dielectric constant increased to 3.12. Thereafter, by performing a recovery treatment with a silane compound, the dielectric constant recovered to 2.39, but it did not return to the value immediately after film formation. However, the dielectric constant was recovered to 2.25, which is close to the value immediately after the film formation, by performing ultraviolet irradiation after the recovery treatment with the silane compound. Further, even after being left in the atmosphere for 1 week, the dielectric constant was 2.26, and the low value was maintained immediately after film formation.

[Comparative Example 4]
An evaluation sample was prepared in the same manner as in Example 1 and Example 2 except that light irradiation and electron beam irradiation were not performed in the step of FIG.

  Table 2 summarizes the results of calculating the dielectric constant of the silica-based porous insulating film after each step and after standing for 1 week in the atmosphere from the capacity measured with a mercury probe.

  As shown in Table 2, the dielectric constant immediately after the formation of the silica-based porous insulating film was 2.24. By polishing this film, the dielectric constant increased to 3.12. Thereafter, by performing a recovery treatment with a silane compound, the dielectric constant recovered to 2.39, but it did not return to the value immediately after film formation. Thereafter, when the substrate was left in the atmosphere for 1 week without light irradiation or electron beam irradiation, the dielectric constant increased to 2.55.

[Example 10]
An evaluation sample was produced in the same manner as in Example 8 except that the heat treatment temperature at the time of light irradiation was changed in the step of FIG. The heat treatment temperatures at the time of light irradiation were 30 ° C., 60 ° C., 100 ° C., 150 ° C., 200 ° C., 250 ° C., 300 ° C., 350 ° C., and 400 ° C., and evaluation samples were prepared for each.

  Table 3 summarizes the results of calculating the dielectric constant of the silica-based porous insulating film immediately after producing the evaluation sample and after being left in the atmosphere for one week from the capacity measured with a mercury probe.

  As shown in Table 3, the dielectric constant of the silica-based porous insulating film 202 immediately after the production of each evaluation sample was substantially constant at 2.24 to 2.26. Further, even after being left in the atmosphere for 1 week, the dielectric constant was 2.24 to 2.26, which was maintained at a low value equivalent to that immediately after the evaluation sample was produced.

[Example 11]
An evaluation sample was produced in the same manner as in Example 9 except that the heat treatment temperature at the time of electron beam irradiation was changed in the step of FIG. The heat treatment temperatures during electron beam irradiation were 30 ° C., 60 ° C., 100 ° C., 150 ° C., 200 ° C., 250 ° C., 300 ° C., 350 ° C., and 400 ° C., and evaluation samples were prepared for each.

  Table 3 summarizes the results of calculating the dielectric constant of the silica-based porous insulating film immediately after producing the evaluation sample and after being left in the atmosphere for one week from the capacity measured with a mercury probe.

  As shown in Table 3, the dielectric constant of the silica-based porous insulating film 202 immediately after the production of each evaluation sample was substantially constant at 2.24 to 2.26. Further, even after being left in the atmosphere for 1 week, the dielectric constant was 2.24 to 2.26, which was maintained at a low value equivalent to that immediately after the evaluation sample was produced.

[Comparative Example 5]
Evaluation samples were prepared in the same manner as in Examples 10 and 11 except that light irradiation and electron beam irradiation were not performed in the step of FIG.

  Table 3 summarizes the results of calculating the dielectric constant of the silica-based porous insulating film immediately after the evaluation sample was created and after being left in the atmosphere for one week from the capacity measured with a mercury probe.

  As shown in Table 3, the dielectric constant of the silica-based porous insulating film 202 immediately after the production of each evaluation sample was 2.34 to 2.39, and those of Examples 10 and 11 where light irradiation or electron beam irradiation was performed. It was higher than the case. In addition, when left in the atmosphere for 1 week, the dielectric constant increased from 2.52 to 2.56.

[Example 12]
Up to the third wiring layer was formed by the semiconductor device manufacturing method according to the fourth embodiment. The ultraviolet irradiation after the damage repair treatment with the silane compound performed after dry etching and polishing was performed in a nitrogen atmosphere. The third wiring layer was formed under the same process conditions as the second wiring layer.

  The yield of 1 million continuous vias was measured using the multilayer wiring of the prototype semiconductor device and found to be 91%. The effective dielectric constant of the interlayer insulating film was measured by interlayer capacitance and found to be 2.60. Further, when the wiring resistance was measured after leaving at 200 ° C. for 1000 hours, no increase in resistance was observed.

[Example 13]
A semiconductor device was manufactured in the same process as in Example 12, except that the ultraviolet irradiation after the damage repair treatment with the silane compound performed after dry etching and polishing was performed in a helium atmosphere. Specifically, ultraviolet irradiation after damage repairing treatment was performed using a high-pressure mercury lamp (UVL-7000H4-N, manufactured by Ushio Electric Co., Ltd.) in a state where the substrate was heated to 400 ° C. in a helium atmosphere, and the wavelength was 200 to 200. This was performed by irradiating 600 nm ultraviolet rays for 10 minutes.

  When the yield of 1 million continuous vias was measured using the multilayer wiring of the prototype semiconductor device, it was 94%. The effective dielectric constant of the interlayer insulating film was measured by interlayer capacitance and found to be 2.58. Further, when the wiring resistance was measured after leaving at 200 ° C. for 1000 hours, no increase in resistance was observed.

[Example 14]
A semiconductor device was manufactured by the same process as in Example 12 except that the ultraviolet irradiation after the damage repair treatment with the silane compound performed after dry etching and polishing was performed in an argon atmosphere. Specifically, ultraviolet irradiation after damage repairing treatment was performed using a high-pressure mercury lamp (UVL-7000H4-N manufactured by Ushio Electric Co., Ltd.) in a state where the substrate was heated to 400 ° C. in an argon atmosphere, and the wavelength was 200 to 200 ° C. This was performed by irradiating 600 nm ultraviolet rays for 10 minutes.

  The yield of 1 million continuous vias was measured using the multilayer wiring of the prototype semiconductor device and found to be 93%. The effective dielectric constant of the interlayer insulating film was measured by interlayer capacitance and found to be 2.61. Further, when the wiring resistance was measured after leaving at 200 ° C. for 1000 hours, no increase in resistance was observed.

[Example 15]
A semiconductor device was manufactured in the same process as in Example 12 except that the ultraviolet irradiation after the damage repair treatment with the silane compound performed after dry etching and polishing was performed in vacuum. Specifically, UV irradiation after damage repair processing is performed using a high-pressure mercury lamp (UVL-7000H4-N, manufactured by USHIO INC.) In a state where the substrate is heated to 400 ° C. in a vacuum, and the wavelength is 200 to 600 nm. The ultraviolet rays were irradiated for 10 minutes.

  The yield of 1 million continuous vias was measured using the multilayer wiring of the prototype semiconductor device and found to be 96%. The effective dielectric constant of the interlayer insulating film was measured by interlayer capacitance and found to be 2.52. Further, when the wiring resistance was measured after leaving at 200 ° C. for 1000 hours, no increase in resistance was observed.

[Example 16]
A semiconductor device was manufactured in the same process as in Example 12 except that electron beam irradiation was performed instead of ultraviolet irradiation after damage repair treatment with a silane compound. The electron beam irradiation was performed by irradiating the substrate at 400 ° C. in vacuum for 1 minute at an acceleration voltage of 10 kV.

  The yield of 1 million continuous vias was measured using the multilayer wiring of the prototype semiconductor device and found to be 90%. The effective dielectric constant of the interlayer insulating film was measured by interlayer capacitance and found to be 2.63. Further, when the wiring resistance was measured after leaving at 200 ° C. for 1000 hours, no increase in resistance was observed.

[Comparative Example 6]
In the process of Example 12, a semiconductor device was manufactured without performing damage repair treatment with a silane compound, light irradiation, and electron beam irradiation treatment.

  The yield of 1 million continuous vias was measured using the multilayer wiring of the prototype semiconductor device and found to be 72%. The effective dielectric constant of the interlayer insulating film was measured by interlayer capacitance and found to be 2.82. Further, when the wiring resistance was measured after leaving at 200 ° C. for 1000 hours, an increase in resistance was observed in 45% of the number of vias.

[Comparative Example 7]
In the process of Example 12, only the damage repair process with the silane compound was performed, and the semiconductor device was manufactured without performing the light irradiation and the electron beam irradiation process.

  When the yield of 1 million continuous vias was measured using the multilayer wiring of the prototype semiconductor device, it was 81%. The effective dielectric constant of the interlayer insulating film was measured by interlayer capacitance and found to be 2.82. Further, when the wiring resistance was measured after leaving at a high temperature of 200 ° C. for 1000 hours, an increase in resistance was observed in 18% of the number of vias.

[Example 17]
Up to the third wiring layer was formed by the semiconductor device manufacturing method according to the fifth embodiment. The ultraviolet irradiation after the damage repair treatment with the silane compound performed after dry etching and polishing was performed in a nitrogen atmosphere. The third wiring layer was formed under the same process conditions as the second wiring layer.

  When the yield of 1 million continuous vias was measured using the multilayer wiring of the prototype semiconductor device, it was 94%. The effective dielectric constant of the interlayer insulating film was measured by interlayer capacitance and found to be 2.49. Further, when the wiring resistance was measured after leaving at 200 ° C. for 1000 hours, no increase in resistance was observed.

[Example 18]
A semiconductor device was manufactured in the same process as in Example 17 except that the ultraviolet irradiation after the damage repair treatment with the silane compound performed after dry etching and polishing was performed in a helium atmosphere. Specifically, ultraviolet irradiation after damage repairing treatment was performed using a high-pressure mercury lamp (UVL-7000H4-N, manufactured by Ushio Electric Co., Ltd.) in a state where the substrate was heated to 400 ° C. in a helium atmosphere, and the wavelength was 200 to 200. This was performed by irradiating 600 nm ultraviolet rays for 10 minutes.

  The yield of 1 million continuous vias was measured using the multilayer wiring of the prototype semiconductor device and found to be 96%. The effective dielectric constant of the interlayer insulating film was measured by interlayer capacitance and found to be 2.47. Further, when the wiring resistance was measured after leaving at 200 ° C. for 1000 hours, no increase in resistance was observed.

[Example 19]
A semiconductor device was manufactured by the same process as in Example 17 except that the ultraviolet irradiation after the damage repair treatment with the silane compound performed after dry etching and polishing was performed in an argon atmosphere. Specifically, ultraviolet irradiation after damage repairing treatment was performed using a high-pressure mercury lamp (UVL-7000H4-N manufactured by Ushio Electric Co., Ltd.) in a state where the substrate was heated to 400 ° C. in an argon atmosphere, and the wavelength was 200 to 200 ° C. This was performed by irradiating 600 nm ultraviolet rays for 10 minutes.

  The yield of 1 million continuous vias was measured using the multilayer wiring of the prototype semiconductor device and found to be 97%. The effective dielectric constant of the interlayer insulating film was measured by interlayer capacitance and found to be 2.47. Further, when the wiring resistance was measured after leaving at 200 ° C. for 1000 hours, no increase in resistance was observed.

[Example 20]
A semiconductor device was manufactured in the same process as in Example 17 except that the ultraviolet irradiation after the damage repair treatment with the silane compound performed after dry etching and polishing was performed in vacuum. Specifically, UV irradiation after damage repair processing is performed using a high-pressure mercury lamp (UVL-7000H4-N, manufactured by USHIO INC.) In a state where the substrate is heated to 400 ° C. in a vacuum, and the wavelength is 200 to 600 nm. The ultraviolet rays were irradiated for 10 minutes.

  The yield of 1 million continuous vias was measured using the multilayer wiring of the prototype semiconductor device and found to be 95%. The effective dielectric constant of the interlayer insulating film was measured by interlayer capacitance and found to be 2.46. Further, when the wiring resistance was measured after leaving at 200 ° C. for 1000 hours, no increase in resistance was observed.

[Example 21]
A semiconductor device was manufactured in the same process as in Example 17 except that electron beam irradiation was performed instead of ultraviolet irradiation after damage repair treatment with a silane compound. The electron beam irradiation was performed by irradiating the substrate at 400 ° C. in vacuum for 1 minute at an acceleration voltage of 10 kV.

  The yield of 1 million continuous vias was measured using the multilayer wiring of the prototype semiconductor device and found to be 93%. The effective dielectric constant of the interlayer insulating film was measured by interlayer capacitance and found to be 2.47. Further, when the wiring resistance was measured after leaving at 200 ° C. for 1000 hours, no increase in resistance was observed.

[Comparative Example 8]
In the process of Example 17, a semiconductor device was manufactured without performing damage repair treatment with a silane compound, light irradiation, and electron beam irradiation treatment.

  The yield of 1 million continuous vias was measured using the multilayer wiring of the prototype semiconductor device and found to be 65%. The effective dielectric constant of the interlayer insulating film was measured by interlayer capacitance and found to be 2.76. Further, when the wiring resistance was measured after leaving at a high temperature of 200 ° C. for 1000 hours, an increase in resistance was observed in 58% of the number of vias.

[Comparative Example 9]
In the process of Example 17, only the damage repair process with the silane compound was performed, and the semiconductor device was manufactured without performing the light irradiation and the electron beam irradiation process.

  The yield of 1 million continuous vias was measured using the multilayer wiring of the prototype semiconductor device, which was 67%. The effective dielectric constant of the interlayer insulating film was measured by interlayer capacitance and found to be 2.75. Further, when the wiring resistance was measured after leaving at 200 ° C. for 1000 hours, an increase in resistance was observed in 26% of the number of vias.

  Regarding the above embodiment, the following additional notes are disclosed.

(Appendix 1) Forming an insulating film of a silica-based insulating material on a semiconductor substrate;
Processing the insulating film;
Making the processed insulating film hydrophobized by acting a silane compound;
And a step of irradiating the insulating film with light or electron beam.

(Additional remark 2) In the manufacturing method of the semiconductor device of Additional remark 1,
In the process of processing the insulating film, the insulating film is processed by dry etching.

(Additional remark 3) In the manufacturing method of the semiconductor device of Additional remark 1,
In the step of processing the insulating film, the insulating film is processed by polishing.

(Appendix 4) In the method for manufacturing a semiconductor device according to any one of appendices 1 to 3,
After the step of processing the insulating film and before the step of causing the silane compound to act on the insulating film, the insulating film is formed of oxygen, argon, hydrogen, nitrogen, or a mixed gas selected from these gases. A method of manufacturing a semiconductor device, further comprising the step of processing with plasma.

(Additional remark 5) In the manufacturing method of the semiconductor device of Additional remark 4,
In the step of processing the insulating film with plasma, a by-product generated in the step of processing the insulating film and attached to the insulating film is removed.

(Appendix 6) In the method for manufacturing a semiconductor device according to any one of appendices 1 to 3,
After the step of processing the insulating film, before the step of allowing the silane compound to act on the insulating film, the by-product generated in the step of processing the insulating film and adhering to the insulating film is removed with a chemical solution. The manufacturing method of the semiconductor device characterized by further including a process.

(Appendix 7) In the method for manufacturing a semiconductor device according to any one of appendices 1 to 6,
The method for performing light irradiation or electron beam irradiation on the insulating film is performed in a temperature range of 30 to 400 ° C. A method for manufacturing a semiconductor device.

(Supplementary note 8) In the method for manufacturing a semiconductor device according to any one of supplementary notes 1 to 7,
The method of performing light irradiation or electron beam irradiation on the insulating film is performed in an atmosphere having an oxygen concentration of 150 ppm or less.

(Supplementary note 9) In the method for manufacturing a semiconductor device according to supplementary note 8,
The method of manufacturing a semiconductor device, wherein the atmosphere is an atmosphere of nitrogen, helium, argon, or a mixed gas of a plurality of gases selected from these.

(Additional remark 10) In the manufacturing method of the semiconductor device of Additional remark 8,
The atmosphere is a vacuum. A method of manufacturing a semiconductor device, wherein:

(Appendix 11) In the method for manufacturing a semiconductor device according to any one of appendices 1 to 10,
The step of causing the silane compound to act on the insulating film is performed in a temperature range of 20 to 350 ° C.

(Appendix 12) In the method for manufacturing a semiconductor device according to any one of appendices 1 to 11,
In the step of causing a silane compound to act on the insulating film, the insulating film is irradiated with vapor containing the silane compound.

(Supplementary note 13) In the method for manufacturing a semiconductor device according to any one of supplementary notes 1 to 11,
In the step of allowing a silane compound to act on the insulating film, the silane compound is applied onto the insulating film by a spin coating method.

(Supplementary Note 14) In the method for manufacturing a semiconductor device according to Supplementary Note 13,
A method of manufacturing a semiconductor device, wherein the silane compound is applied on the insulating film and then heated in a temperature range of 50 to 350 ° C.

(Supplementary note 15) In the method for manufacturing a semiconductor device according to any one of supplementary notes 1 to 14,
The method of manufacturing a semiconductor device, wherein the silane compound is a silazane silane compound, an amide silane compound, an alkoxy silane compound, or an acetoxy silane compound.

(Supplementary Note 16) In the method for manufacturing a semiconductor device according to any one of supplementary notes 1 to 15,
The said insulating film is a laminated film containing a porous silica type insulating film. The manufacturing method of the semiconductor device characterized by the above-mentioned.

(Supplementary note 17) In the method for manufacturing a semiconductor device according to any one of supplementary notes 1 to 15,
The method for manufacturing a semiconductor device, wherein the insulating film is a laminated film including a SiOC film formed by a plasma CVD method.

(Appendix 18) A step of forming an insulating film of a silica-based insulating material on a semiconductor substrate;
Forming an opening in the insulating film by dry etching;
Forming a conductive film on the insulating film in which the opening is formed;
Removing the conductive film on the insulating film by polishing, and forming a wiring including the conductive film embedded in the opening,
A step of hydrophobizing the insulating film by acting a silane compound between at least one of the step of forming the opening and the step of forming the conductive film and after the step of forming the wiring; The method further includes the step of performing light irradiation or electron beam irradiation on the insulating film.

(Supplementary note 19) In the method for manufacturing a semiconductor device according to supplementary note 18,
In the step of forming the insulating film, the first insulating film and the second insulating film formed on the first insulating film are formed,
In the step of forming the wiring, the second insulating film is removed together with the conductive film. A method of manufacturing a semiconductor device, wherein:

(Supplementary note 20) In the method for manufacturing a semiconductor device according to supplementary note 19,
The method for manufacturing a semiconductor device, wherein the second insulating film is a hard mask for forming the opening.

FIG. 1 is a flowchart showing a method for manufacturing a semiconductor device according to a first embodiment of the present invention. FIG. 2 is a process cross-sectional view (part 1) illustrating the method for manufacturing the semiconductor device according to the first embodiment of the invention. FIG. 3 is a process cross-sectional view (No. 2) showing the method for manufacturing the semiconductor device according to the first embodiment of the invention. FIG. 4 is a process cross-sectional view (part 1) illustrating the method for manufacturing the semiconductor device according to the second embodiment of the invention. FIG. 5 is a process cross-sectional view (part 2) illustrating the method for manufacturing the semiconductor device according to the second embodiment of the present invention. FIG. 6 is a process cross-sectional view (part 3) illustrating the method for manufacturing the semiconductor device according to the second embodiment of the invention. FIG. 7 is a process cross-sectional view (No. 4) showing the method for manufacturing the semiconductor device according to the second embodiment of the invention. FIG. 8 is a process cross-sectional view (No. 5) showing the method for manufacturing the semiconductor device according to the second embodiment of the invention. FIG. 9 is a process cross-sectional view (No. 6) showing the method for manufacturing the semiconductor device according to the second embodiment of the invention. FIG. 10 is a process cross-sectional view (No. 7) showing the method for manufacturing the semiconductor device according to the second embodiment of the invention. FIG. 11 is a process cross-sectional view (No. 8) illustrating the method for manufacturing the semiconductor device according to the second embodiment of the invention. FIG. 12 is a process cross-sectional view (No. 9) showing the method for manufacturing the semiconductor device according to the second embodiment of the invention. FIG. 13 is a process cross-sectional view (No. 10) illustrating the method for manufacturing the semiconductor device according to the second embodiment of the invention. FIG. 14 is a process cross-sectional view (No. 11) illustrating the method for manufacturing the semiconductor device according to the second embodiment of the invention. FIG. 15 is a flowchart showing a method of manufacturing a semiconductor device according to the third embodiment of the present invention. FIG. 16 is a process cross-sectional view illustrating the semiconductor device manufacturing method according to the third embodiment of the present invention. FIG. 17 is a process cross-sectional view (No. 1) illustrating the method for manufacturing the semiconductor device according to the fourth embodiment of the invention. FIG. 18 is a process cross-sectional view (part 2) illustrating the method for manufacturing the semiconductor device according to the fourth embodiment of the invention. FIG. 19 is a process cross-sectional view (Part 3) illustrating the method for manufacturing the semiconductor device according to the fourth embodiment of the present invention. FIG. 20 is a process cross-sectional view (part 4) illustrating the method for manufacturing the semiconductor device according to the fourth embodiment of the invention. FIG. 21 is a process cross-sectional view (No. 5) showing the method for manufacturing the semiconductor device according to the fourth embodiment of the invention. FIG. 22 is a process cross-sectional view (part 1) illustrating the method for manufacturing the semiconductor device according to the fifth embodiment of the invention. FIG. 23 is a process cross-sectional view (part 2) illustrating the method for manufacturing the semiconductor device according to the fifth embodiment of the invention. FIG. 24 is a process cross-sectional view (part 3) illustrating the method for manufacturing the semiconductor device according to the fifth embodiment of the invention. FIG. 25 is a process cross-sectional view (No. 4) showing the method for manufacturing the semiconductor device according to the fifth embodiment of the invention. FIG. 26 is a process cross-sectional view (No. 5) showing the method for manufacturing the semiconductor device according to the fifth embodiment of the invention. It is process sectional drawing which shows the manufacturing method of the evaluation sample used in order to verify the effect of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Semiconductor substrate 12 ... Element isolation film 14 ... Element region 16 ... Gate insulating film 18 ... Gate electrode 22 ... Source / drain region 24 ... MOS transistor 26 ... Interlayer insulating film 28 ... Stopper film 30 ... Contact holes 32, 48, 74 ... Barrier metal 34 ... Tungsten film 35, 77a ... Contact plugs 36, 40, 52, 56, 60, 78 ... Insulating films 38, 54, 58 ... Porous interlayer insulating films 42, 62, 68 ... Photoresist film 44, 64, 70 ... openings 46, 72 ... wiring grooves 50, 76 ... Cu films 51, 77b ... wiring 52, 78 ... Cu diffusion preventing insulating film 66 ... via hole 100 ... base substrate 102 ... insulating film 104 ... hard mask 106 ... Photoresist films 108, 110 ... Opening 112 ... Damaged layer 114 ... Side wall deposit 116 ... Repair layer 200 ... Underlying substrate 02 ... insulating film 204 ... damaged layer 206 ... repair layer 300 ... silicon substrate 302 ... silica-based porous dielectric film 304 ... damaged layer 306 ... repair layer

Claims (10)

Forming an insulating film of a silica-based insulating material on a semiconductor substrate;
Processing the insulating film;
Making the processed insulating film hydrophobized by acting a silane compound;
And a step of performing light irradiation or electron beam irradiation on the insulating film after the step of hydrophobizing the insulating film . In the manufacturing method of the semiconductor device according to claim 1,
After the step of processing the insulating film and before the step of causing the silane compound to act on the insulating film, the insulating film is formed of oxygen, argon, hydrogen, nitrogen, or a mixed gas selected from these gases. A method of manufacturing a semiconductor device, further comprising the step of processing with plasma. In the manufacturing method of the semiconductor device of Claim 1 or 2,
The method for performing light irradiation or electron beam irradiation on the insulating film is performed in a temperature range of 30 to 400 ° C. A method for manufacturing a semiconductor device. In the manufacturing method of the semiconductor device according to any one of claims 1 to 3,
The method of performing light irradiation or electron beam irradiation on the insulating film is performed in an atmosphere having an oxygen concentration of 150 ppm or less. In the manufacturing method of the semiconductor device according to claim 4,
The method of manufacturing a semiconductor device, wherein the atmosphere is an atmosphere of nitrogen, helium, argon, or a mixed gas of a plurality of gases selected from these. In the manufacturing method of the semiconductor device according to claim 4,
The atmosphere is a vacuum. A method of manufacturing a semiconductor device, wherein: In the manufacturing method of the semiconductor device according to claim 1,
The step of causing the silane compound to act on the insulating film is performed in a temperature range of 20 to 350 ° C. In the manufacturing method of the semiconductor device according to any one of claims 1 to 7,
In the step of causing a silane compound to act on the insulating film, the insulating film is irradiated with vapor containing the silane compound. In the manufacturing method of the semiconductor device according to any one of claims 1 to 7,
In the step of allowing a silane compound to act on the insulating film, the silane compound is applied onto the insulating film by a spin coating method. Forming an insulating film of a silica-based insulating material on a semiconductor substrate;
Forming an opening in the insulating film by dry etching;
Forming a conductive film on the insulating film in which the opening is formed;
Removing the conductive film on the insulating film by polishing, and forming a wiring including the conductive film embedded in the opening,
A step of hydrophobizing the insulating film by acting a silane compound between at least one of the step of forming the opening and the step of forming the conductive film and after the step of forming the wiring; After the step of hydrophobizing the insulating film, the method further includes a step of performing light irradiation or electron beam irradiation on the insulating film.

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