JP2003059921A - Method of forming insulator film and method of manufacturing capacitor member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of forming an insulator film which enables to improve the productivity by simplifying a process, while preventing the decline in productivity even when forming a thick insulator film. SOLUTION: On a wafer W which is formed with a lower electrode layer 200 and a barrier layer 201, a metal oxide film 202 constituted of a Ta oxide film is formed by MO-CVD. Then, the wafer W is rapidly heated by a lamp at 650 deg.C or below, while supplying the steam onto the wafer W at nearly the atmospheric pressure, to form an oxidized and reformed metal oxide film 204 on the wafer W. In the same chamber, the wafer W is annealed at 700 deg.C or above to form a crystallized metal oxide film 206. Then, an upper electrode layer 207 is formed to obtain a capacitor member with a dielectric layer 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming an insulator film and a method for manufacturing a capacitor member, and more specifically, a method for forming an insulator film containing a metal oxide on a substrate, and the insulation. The present invention relates to a method for manufacturing a capacitor member including a dielectric layer including a body film.

[0002]

2. Description of the Related Art In recent years, with the miniaturization of semiconductor devices such as logic elements and memory elements, there has been an increasing demand for thinner insulator films constituting capacitors, resistors and the like. Further, the capacitance C of the capacitor is theoretically proportional to the area A and the dielectric constant ε and inversely proportional to the inter-electrode distance d, as expressed by the following formula (1); C = A · ε / d. In addition to thinning, an insulating film (high dielectric film) having a higher dielectric constant is desired. Moreover, since the dielectric constant of a substance is mainly determined by the physical properties of the material, processes and devices using a material that inherently exhibits a high dielectric constant are already in the stage of practical use or trial production.

The process of forming a metal dielectric film, particularly a dielectric film containing tantalum (Ta), as the high dielectric film is a promising core technology for manufacturing next-generation memory devices of gigabit class or higher. is there. Such Ta
As a manufacturing process of the chip capacitor of the containing film, for example, the following method can be mentioned.

First, (1) a silicon (Si) wafer W is doped with a certain amount of a specific impurity to form a lower electrode layer,
(2) A barrier layer for blocking oxygen, for example, a silicon nitride film is formed thereon. Next, (3) a Ta oxide film is formed on the barrier layer by the CVD method. Then
In order to promote passivation of the Ta oxide film (4), the Ta oxide film is further oxidized by oxygen (O ₂ ) oxidation or UV ozone (O ₃ ) oxidation by remote plasma. Subsequently, in order to further increase the dielectric constant by crystallization (5), the Ta oxide film is annealed to form a Ta-containing dielectric film, and then (6)
Further, titanium nitride or the like is formed as an upper electrode layer to form a MIS.
To obtain a mold type capacitor member.

[0005]

However, in such a conventional method, it is necessary to carry out each step in a separate chamber apparatus, and it takes time and labor to transfer (transfer) a wafer between each step. Further, in the case of a memory device such as a DRAM, the operating voltage is about 1.5 V at maximum, and the film thickness of the Ta-containing dielectric film of the capacitor is generally about 80Å. In such a thin film, the above-mentioned O ₂ oxidation or UV-
O ₃ oxidation can oxidize and reform the entire film thickness.

On the other hand, for example, in the case of a linear capacitor, the design rule of 0.35 μm is 3.5 to 3.5.
A voltage of the order of 5V can be applied. Therefore, it is necessary to increase the film thickness to some extent in order to improve the pressure resistance. However, as the film thickness increases, conventional O ₂ oxidation or UV-
O ₃ oxidation makes it difficult to sufficiently oxidize the deep portion of the film.
In order to eliminate such inconvenience, it is necessary to repeat the film formation and the oxidation a plurality of times, resulting in a significant decrease in throughput. Further, if recrystallized in that state, the withstand voltage characteristic is deteriorated.

Therefore, the present invention has been made in view of the above circumstances, and simplifies the process and reduces the frequency of carrying members to improve productivity, and forms a thick insulator film. Also in this case, it is an object of the present invention to provide a method for forming an insulating film and a method for manufacturing a capacitor member, which can prevent deterioration of productivity and characteristics.

[0008]

In order to solve the above problems, the method for forming an insulator film according to the present invention is a method for forming an insulator film containing a metal oxide on a substrate, The first step of forming a first film containing metal atoms, and heating the substrate while supplying a gas containing water vapor (H ₂ O) onto the substrate having the first film to form the first film. A second step of reforming into a second film, and heating the substrate while supplying oxygen (O ₂ ) gas onto the substrate having the second film to turn the second film into a third film. And a third step of reforming.

In the method of forming an insulator film having such a structure, a first film such as a metal film or a metal oxide film is formed in the first step. Specifically, for example, when forming an insulating film as a high dielectric film, PET (Pe
A Ta oxide film as a first film is formed by the MO-CVD method using an organic Ta source such as alkoxy tantalum such as ntaEthoxyTantal). The oxide of Ta is most stable in the form of a pentavalent compound, that is, Ta ₂ O ₅ , but the film immediately after being formed by the MO-CVD method (corresponding to the “first film”) is In many cases, it does not have such a stoichiometric composition, and in that state, it may exhibit properties as a metal film, and cannot be a perfect insulator film. Further, when a metal film is formed as the first film, it is necessary to make it an insulator by oxidation.

Therefore, the second step is carried out to oxidize the first film with water vapor (so-called wet oxidation).
To form a film. The first film usually exhibits an amorphous state, that is, an amorphous state, and by performing the second step in such a state, sufficient and efficient oxidation is achieved. Here, as a method of supplying the gas containing water vapor onto the substrate, hydrogen (H ₂ ) and oxygen (O ₂ ) are previously burned outside the chamber in which the substrate can be stored to generate water,
Examples thereof include a method of introducing the vaporized state onto the substrate (wet oxidation by a so-called external combustion method) and the like.

In the second step, when the gas containing steam is supplied onto the substrate and the substrate is heated to a certain temperature, the steam receives thermal energy from the substrate immediately above the substrate and various active species are generated. Occurs. Then, the active species as the oxidizing factor diffuse in the first film and oxidize the first film. Since this oxidation reaction is mainly controlled by the diffusion process, even if the thickness of the first film is increased, the oxidation reaction progresses sufficiently and rapidly over the entire film.

As the heating method for the substrate, a rapid heating method is desirable. That is, in the second step, RTA (Rapid Thermal Annealin) combined with wet oxidation is used.
g) or RTO (Rapid Thermal Oxidation) is preferable in that the oxidation efficiency and throughput of the first film can be increased. Moreover, when the Si nitride film or the like is provided as the base of the first film, the oxidation of the nitride film can be suppressed as much as possible. Further, as the gas containing water vapor, in addition to only water vapor, a mixed gas of other gas containing oxygen atoms (for example, O ₂ , N ₂ O, etc.) and water vapor may be supplied onto the substrate.

The second film thus obtained is a film having a substantially stoichiometric composition as a metal oxide film, that is, substantially Ta _{2 in} the case of the Ta oxide film described above.
This is a film having a composition of O ₅ , and the first film has been modified, specifically, passivated. The second film thus formed can function as an insulator film and eventually a dielectric film in this state, but it is obtained by oxidizing the first film in an amorphous state and is amorphous. Has
Not crystallized.

Therefore, in the third step, the substrate is heated or annealed while supplying a gas containing oxygen atoms such as O ₂ onto the substrate. As a result, the third film is formed which is capable of crystallizing the second film and sufficiently increasing the degree of crystallinity thereof and exhibiting a high dielectric constant. Thus, in the third step, the supply gas onto the substrate is changed from the gas containing water vapor to O ₂ gas.
By changing to the gas, and by adjusting the heating temperature and the like as necessary, the second step can be continuously performed without interruption. Therefore, members such as an apparatus and a container used in the second step and the third step can be shared with each other, which makes it unnecessary to transfer or move the substrate between both steps. Also,
The steps can be easily switched by simply changing the gas, adjusting the heating temperature, and the like. Therefore, the second and third steps can be regarded as one normal step.

Further, as described above, since the oxidation reaction in the second step is mainly governed by the diffusion of the oxidation factor in the film, the optimum oxidation is controlled by controlling the diffusion constant or the diffusion rate of the oxidation factor. Processing can take place. This diffusion constant or diffusion rate largely depends on the temperature of the substrate and the atmospheric pressure around it, and the amount of oxidation also depends on the processing time.

Therefore, in the second step, the pressure around the substrate, the heating temperature of the substrate, the processing time of the substrate, or these, depending on the type of the first film, the film thickness, or the film forming conditions thereof. It is preferable to control a plurality of combinations. This makes it possible to optimize the oxidation reaction in the second step. In wet oxidation, the diffusion of the oxidation factor is fast, and the underlayer is easily oxidized depending on the film thickness of the first film. Therefore, by adjusting the diffusion constant in consideration of such a tendency, the oxidation of the underlayer is suppressed. Can be effectively suppressed.

More specifically, in the second step,
The pressure around the substrate is preferably 66 kPa to 102 kP
a (500 to 760 Torr), more preferably 80 k
Pa to 102 kPa (600 to 760 Torr) is suitable. If this pressure is less than 66 kPa, the density of the active species serving as an oxidation factor may not be sufficiently increased depending on the type of the first film, and the reactivity or reaction rate of the oxidation reaction may not be sufficiently increased. . On the other hand, this pressure is 10
When the pressure exceeds 2 kPa, that is, the atmospheric pressure, it is necessary to adjust the pressure using a pressurizing means, and the handling tends to be complicated as compared with depressurization or simple exhaust.

Further, depending on the type of the underlayer of the first film, it is necessary to limit the thermal budget to a certain value or less. By increasing the heating temperature of the substrate, the diffusion constant of the oxidation factor in the first film and Controlling the diffusion rate can be difficult. Even in such a case, by adjusting the pressure around the substrate within the above-mentioned preferable range, the diffusion constant and the like can be easily and desirably adjusted without raising the heating temperature of the substrate.

Further, in the second step, the heating temperature of the substrate is preferably 650 ° C. or lower, more preferably 500 to 650 ° C., and in the third step, the heating temperature of the substrate is preferably 700 ° C. or higher. , And more preferably 7
It is useful to set the temperature to 50 to 850 ° C. Furthermore, the third
In the process of 1, it is preferable to perform rapid heating / cooling, that is, spike annealing. More specifically, the temperature is raised at 100 to 150 ° C / sec (ramp up).
However, it is preferable to lower the temperature (ramp down) at 50 to 90 ° C./sec.

The heating temperature of the substrate in the second step is 65
When the temperature exceeds 0 ° C., the first film starts to crystallize, for example, Ta
With oxides, crystallization significantly progresses at around 700 ° C. It is difficult to reoxidize the film crystallized in this way, and it is necessary to reoxidize the Ta oxide at 700 ° C. or lower. Thus, from the viewpoint of suppressing crystallization of the first film, it is desirable to set the upper limit of the heating temperature of the substrate in the second step to 650 ° C.

If the temperature exceeds 650 ° C., the heat input to the substrate may increase and the thermal budget limit may be exceeded, depending on the first film thickness and the processing time. In particular, when an underlayer serving as an electrode layer is doped with impurities, there is a possibility that the impurities may undesirably diffuse. From these, when the heating temperature of the substrate in the second step exceeds 650 ° C., it tends to be difficult to control the oxidation reaction by adjusting the pressure around the substrate and the heat treatment time.

On the other hand, when the heating temperature of the substrate in the third step is lower than 700 ° C., the crystallization of the metal oxide does not proceed sufficiently and it becomes difficult to increase the dielectric constant of the third film to a desired value. . For example, as described above, the desirable annealing temperature (crystallization temperature) for Ta oxide is 700 ° C. or higher,
More preferably, it is 800 ° C. or higher. Moreover, when spike annealing is performed, crystallization tends to proceed instantaneously. Therefore, when the Si electrode layer or the like is provided as the underlayer, if the heating time is excessively lengthened, the underlayer may be oxidized.

In this case, a Si oxide film having a low dielectric constant is formed, and that portion also functions as a dielectric, so that the substantial thickness of the dielectric layer (distance d between electrodes in the above formula (1)) becomes large. As a result, the capacitance C of the capacitor is reduced. In addition, when a Ta-containing dielectric film is used as the metal dielectric film, the underlying layer generally has a smaller dielectric constant than the Ta-containing dielectric film, so that the effective dielectric constant of the dielectric layer is lowered and the capacitance further increases. It causes a decrease in C. From this point, there is an advantage that rapid heating is performed by spike annealing and then rapid cooling.

Even in the above conventional method, 700 ° C.
Although the above annealing can be performed, if wet oxidation is attempted by simply using an annealing apparatus for that purpose (for example, a heating furnace (Furnace)) as it is, as described above, depending on the thickness of the first film, the underlying layer may be formed. There is a very high possibility that the oxidation of will proceed instantaneously. This point is considered to be one of the main reasons why wet oxidation has not been conventionally applied to the oxidation treatment of the insulating film functioning as a metal dielectric film.

Further, as described above, the metal used for the first film is not particularly limited, and those having a sufficiently large intrinsic dielectric constant are preferable, for example, Ta, BST, ST, or a mixture thereof. Is mentioned. With these, the third
Films of Ta ₂ O ₅ and ((Ba, Sr) Ti
O ₃ ), SrTiO _{3 and the} like are formed. Above all, Ta
Has a dielectric constant ε of about 25 and is a nitride film (Si _x N _y is 7
), Other oxides (about 3.5 to 4), etc. exhibiting a significantly higher dielectric constant, and since it has a track record of use, it can be said to be a material suitable for practical use. That is, in the first step, it is desirable to form a first film containing Ta atoms as metal atoms.

Furthermore, in recent years, the miniaturization of semiconductor devices has been rapidly accelerated, but the performance of capacitors and resistors used for these is often determined by the material characteristics, and the device area occupied by capacitors and the like has been so far. The limit is beginning to be seen in the dramatic reduction. According to a certain calculation, it is said that the capacitor and the resistor will occupy about 30% of the area on the element chip as the design rule progresses. Therefore, if the present invention is applied, the process can be simplified, and by using a high dielectric material such as Ta while suppressing the oxidation of the underlayer, it is possible to contribute to further reduction of the capacitor region and the like.

Further, the method for manufacturing a capacitor member according to the present invention is a method effectively implemented by applying the method for forming an insulator film according to the present invention, and the first electrode for forming the first electrode layer on the base body. A layer forming step, and a dielectric layer forming step of forming an insulator film on the first electrode layer by the method of forming an insulator film according to the present invention to form a dielectric layer including the insulator film; And a second electrode layer forming step of forming a second electrode layer on the dielectric layer.

Further, a barrier layer forming step of forming a barrier layer between the first electrode layer and the dielectric layer may be further provided. This barrier layer restricts or blocks the inflow of oxygen active species, which is an oxidizing factor, into the first electrode layer when the first film is wet-oxidized in the second step. Further, the barrier layer serves as an underlayer of the first film, and when the above-mentioned conventional method is used especially when the first film is thin, the barrier layer is easily oxidized, whereas the barrier film of the present invention is formed. By using the forming method, the first film can be oxidized with high efficiency, and the oxidation of the barrier layer can be effectively suppressed to prevent the effective dielectric constant from lowering.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. The same elements will be denoted by the same reference symbols, without redundant description. Unless otherwise specified, the positional relationship such as top, bottom, left and right is based on the positional relationship such as top, bottom, left and right in the drawings.

FIG. 1 is a flow chart showing the procedure of a preferred embodiment of the method for manufacturing a capacitor member of the present invention using the method for forming an insulator film according to the present invention. Also, FIG.
FIG. 2 is a schematic cross-sectional view showing an example of a processing device for carrying out a part of the flow shown in FIG. 1. Furthermore, FIG.
(F) is a process drawing schematically showing a state in which a capacitor member is manufactured according to the procedure shown in FIG. 1. First, HSG or Doped Si (Hemispherical G) containing impurities at a predetermined concentration is formed on a wafer W made of Si as a substrate.
A rained silicon film is formed to form the lower electrode layer 200 (step S1, first electrode layer forming step; FIG. 3).
(See (A)).

Next, as a pretreatment, after cleaning for removing the natural oxide film, the wafer W is subjected to normal RTN.
(Rapid Thermal Nitridation) Transferred to the chamber (step S2), the surface portion of the HSG film forming the lower electrode layer 200 is nitrided and formed of a Si _x N _y film (Si ₃ N ₄ film) to form a barrier layer 201. (Step S3, barrier layer forming step; see FIG. 3B).

Next, the wafer W is transferred to the CVD chamber (step S4), and the metal oxide film 202 made of Ta oxide film (Ta _x O _y ) is formed on the barrier layer 201 by MO-CV.
A film is formed by the D method (step S51, first step; refer to FIG. 3C). For example, PET or the like is used as the film raw material. Next, the wafer W is processed by the processing apparatus 1 shown in FIG.
Transfer to 0 (step S52). The processing apparatus 10 includes a susceptor 12 that supports a wafer W in a chamber 11,
The heating lamp unit 14 is provided so as to face the susceptor 12 and is connected to the power source PS.

The susceptor 12 is connected to a drive mechanism 13 that moves and rotates the susceptor 12 up and down. on the other hand,
The heating lamp unit 14 is provided with a plurality of heating lamps (not shown), and the susceptor 12 uses radiation and heat conduction.
The wafer W placed on it is heated rapidly. The side wall of the chamber 11 has a gas supply port Pi.
And a gas exhaust port Po are provided, and a gas supply system 16 and a gas exhaust system 18 are connected to each. The gas supply system 16 is an external combustion-type steam supply source 16a that combusts H ₂ gas and O ₂ gas to generate steam, and
It has an O ₂ gas supply source 16b and MFCs (mass flow rate controllers) Ma and Mb connected to each through piping.

The wafer W transferred to the processing apparatus 10 having such a configuration is set on the susceptor 12, and the driving mechanism 13 is operated to set the distance between the wafer W and the heating lamp section 14 to a predetermined distance. Next, the chamber 11 is evacuated, and an inert gas (not shown) is supplied as necessary to supply the chamber 1
The inside of 1 is replaced with gas. When the pressure in the chamber 11 reaches a predetermined pressure, the gas supply system 16 supplies a mixed gas of water vapor and O ₂ gas as the gas G into the chamber 11 while operating the gas exhaust system 18. Alternatively, the O ₂ gas may be supplied prior to the supply of the steam, and the steam may be supplied after the O ₂ atmosphere is formed.

Almost at the same time as the supply of the gas G, the drive mechanism 13 rotates the susceptor 12 to rotate the wafer W, and at the same time, the heating lamp section 14 is turned on. As a result, the upper surface side of the wafer W is heated while the gas G is flowing over the wafer W, and the temperature of the wafer W is rapidly increased from room temperature.

When the temperature of the wafer W reaches a predetermined temperature, the gas G is given thermal energy from the surface portion of the wafer W to generate active species derived from water vapor and O ₂ gas, and the entire metal oxide film 202 contains these species. Exposed to active species. Of the active species, oxygen active species mainly containing oxygen atoms function as an oxidizing factor and diffuse into the metal oxide film 202. Here, the metal oxide film 202 exhibits an amorphous state, that is, an amorphous state, is not a complete oxide film, and is used as a metal-metal bond (Ta-Ta metal bond) or an organic metal source. The contained hydrogen (H) or carbon (C) may have a part bonded to Ta, or may have a dangling bond.

The metal oxide film 202 is formed by the diffusion of the oxidizing factor.
The energy of the active species is given to these bonds in the inside to dissociate the bonds, and oxygen atoms are bonded to the portions to promote the oxidation reaction of Ta atoms. Also, dangling bonds tend to be terminated by oxygen atoms. By such wet oxidation, the metal oxide film 202 is oxidized and modified, and the metal oxide film 204 having a composition stoichiometrically close to Ta ₂ O ₅ is formed.
Are formed (step S53, second step; FIG. 3).
(D)).

Here, the wafer W in step S53
The heating temperature is preferably 650 ° C. or lower, and more preferably 500 to 650 ° C. This temperature is 650 ℃
When it exceeds, the metal oxide film 202 starts to crystallize, and, for example, in the case of Ta oxide, the crystallization significantly progresses at around 700 ° C. Re-oxidation in such a crystallized film tends to be extremely difficult. Therefore, by setting the upper limit of the heating temperature of the wafer W in step S53 to 650 ° C., it becomes possible to oxidize the metal oxide film 202 while maintaining the amorphous state, and it is possible to prevent the reoxidation efficiency of the metal oxide film 202 from decreasing. .

If this temperature exceeds 650 ° C., the wafer W will depend on the thickness of the metal oxide film 202 and the processing time.
The amount of heat input into the lower electrode layer 200 may exceed the limit of the thermal budget, resulting in inconvenient diffusion of impurities doped in the lower electrode layer 200. Therefore, when the heating temperature of the wafer W exceeds 650 ° C., it becomes difficult to control the reaction by the pressure in the chamber 11 and the heat treatment time.

Further, the chamber 1 in step S53
The pressure inside 1 or the pressure around the wafer W is preferably 66 kPa to 102 kPa (500 to 760 T).
orr), more preferably 80 kPa to 102 kPa
(600 to 760 Torr). This pressure is 66k
If it is less than Pa, the oxidation reaction of the metal oxide film 202 tends not to proceed sufficiently. On the other hand, this pressure is 102 kP
When the pressure exceeds a (atmospheric pressure), it is necessary to provide a pressurizing system in the chamber 11 in addition to the gas exhaust system 18, which complicates the apparatus configuration and lowers handleability and controllability.

Further, even if the heating temperature of the wafer W is set to the above-mentioned suitable temperature range, if the thickness of the metal oxide film 202 is extremely thin, the barrier layer 201 and the lower electrode layer 200 may be oxidized. On the other hand, for example, the barrier layer 201 and the lower electrode layer 2 with respect to the process parameters such as the film forming conditions, the type, the film thickness, and other film forming conditions of the metal oxide film
The conditions of temperature, pressure, and processing time at which the diffusion of the active species, which is an oxidizing factor, into O.O. And
In step S53, the actually formed metal oxide film 202
It is desirable to appropriately control the heating temperature of the wafer W, the internal pressure of the chamber 11, and the processing time according to the type, the film thickness, and the like.

Then, after a lapse of a predetermined time, the supply of steam from the steam supply source 16a is stopped and the gas G
Only ₂ gases are supplied into the chamber 11. Further, the lamp heating by the heating lamp unit 14 is further carried out by further increasing the heat output. The metal oxide film 204 is formed by being sufficiently oxidized in step S53 and has an amorphous property. In such a low crystallinity state, the high dielectric constant inherent in the material is difficult to develop.

Therefore, by RTA treatment by lamp heating in an O ₂ atmosphere, the metal oxide film 204 is sufficiently annealed to promote crystallization of Ta ₂ O ₅ , and a metal that can exhibit an inherently high dielectric constant. The oxide film 206 (third film, insulator film) is formed (step S54, third step; FIG. 3).
(See (E)). And, substantially, this metal oxide film 2
The dielectric layer 20 is composed of 04 and the barrier layer 201 which is the underlying layer.

Here, the wafer W in step S54
The heating temperature is preferably 700 ° C. or higher, more preferably 750 to 850 ° C. This temperature is 700 ℃
If it is less than the range, crystallization of the metal oxide film 204 tends not to proceed sufficiently. Further, if the temperature is 800 ° C. or higher, crystallization can be further promoted, but the amount of heat input to the wafer W is reduced to eliminate the thermal influence on the device characteristics, and the wafer W is not warped or bent due to heat input. From the viewpoint of preventing the change in shape, it is useful to set the temperature below the upper limit temperature.

Further, in step S54, it is more preferable to perform rapid heating / cooling by spike annealing. In this case, for example, processing conditions such that the temperature is raised (ramp up) at 100 to 150 ° C./sec and the temperature is lowered (ramp down) at 50 to 90 ° C./sec can be adopted. When spike annealing is performed, crystallization of the metal oxide film 204 tends to proceed instantaneously. Therefore, if the heating time is excessively lengthened, the barrier layer 201 is oxidized and the SiNO film, SiO
There is a possibility that an oxide film such as a film or a SiO ₂ film is generated, and that the interface portion of the lower electrode layer 200 is also oxidized.

The dielectric constant of such an oxide film is about 3.5 to 4, which is considerably smaller than the dielectric constant of Ta and the dielectric constant of the barrier layer 201, and thus the dielectric layer 2 to be finally formed.
The effective dielectric constant of 0 may be significantly reduced. Therefore, it is useful to prevent the wafer W from being heated more than necessary due to the rapid cooling.

Then, after a lapse of a predetermined time, the rotation of the wafer W is stopped and the heat output of the heating lamp section 14 is adjusted to a predetermined wafer unloading temperature. Further, the operation of the gas supply system 16 and the gas exhaust system 18 is stopped. Then, the wafer W is transferred to the CVD chamber (step S55). Thus, the steps of forming the dielectric layer 20 (step S5), which is an embodiment of the method for forming an insulating film according to the present invention, are constituted from steps S51 to S55.

Further, in the transfer destination CVD chamber, a TiN film is formed on the metal oxide film 206 by the CVD method, and if necessary, heat treatment, plasma treatment or the like is performed to carry out the upper electrode layer 207 (second electrode layer). ) To form M
An IS type capacitor member 2 is obtained (step S6, second
Electrode layer forming step; see FIG. 3 (F). In addition, in FIG.
A more detailed sectional shape of the capacitor member 2 corresponding to FIG.

According to such an insulating film forming method of the present invention and a capacitor member manufacturing method using the same, step S53, which is an oxidation treatment of the metal oxide film 202, is subjected to rapid heating combined with wet oxidation. Since the process is performed by the process, step S54, which is the subsequent annealing process of the metal oxide film 204, can be continuously performed in the same chamber 11 as in step S53. Therefore, as compared with the case of performing the conventional O ₂ oxidation or UV-O ₃ oxidation and then performing the annealing treatment in a heating furnace or the like, the wafer transfer process during that period can be omitted.

Further, since steps S53 and S54 can be continuously carried out in the same chamber 11, they can be regarded as one process, so to speak, and also in this respect, the number of processes can be reduced. Therefore, the simplification of the process can be realized, and the frequency of carrying the wafer W is reduced, so that the productivity of the capacitor member 2 can be improved. Furthermore, as the device configuration, O ₂ oxidation by a conventional remote plasma or UV-
The radio frequency (RF) generator, O ₃ generator, etc., which were required for O ₃ oxidation, are unnecessary. Therefore, the device configuration can be simplified and the economical efficiency can be improved.

Further, in step S53, water vapor is supplied onto the wafer W, and wet oxidation by diffusion of active species generated by heating is used, so that the efficiency of the oxidation reaction of the metal oxide film 202 can be significantly improved. Therefore, even when the film thickness of the metal oxide film 204 is required to be thicker, the oxidation treatment can be performed in one step, so that the productivity and the pressure resistance can be sufficiently reduced in this case. Can be prevented.

Further, when wet oxidation having a high oxidation rate (efficiency) is used as described above, the barrier layer 2 as an underlayer is used.
01 or the lower electrode layer 200 may be oxidized, whereas according to the present invention, it may be an oxidation factor for the barrier layer 201 or the lower electrode layer 200, depending on the type and thickness of the metal oxide film 202. The pressure around the wafer W in the chamber 11, the heating temperature of the wafer W, the processing time thereof, or a combination thereof is controlled so that the diffusion of the active species is not significant.

Therefore, the barrier layer 201 and the lower electrode layer 20 are maintained while maintaining a high oxidation rate for the metal oxide film 202.
Oxidation of 0 can be sufficiently prevented, and a decrease in the effective dielectric constant of the dielectric layer 20 can be suppressed. Moreover, the metal oxide film 20
Since the dielectric constant specific to Ta is developed in 6, it is possible to obtain the capacitor member 2 in which the effective dielectric constant of the dielectric layer 20 is remarkably increased. Therefore, the capacitor member 2 is very useful for other high dielectric film applications such as DRAM, RF-CMOS, and linear capacitor.

Furthermore, in step S53,
Since the water vapor generated by the external combustion is supplied onto the wafer W in that form, the wafer W is not exposed to H ₂ gas which is a combustion raw material having a reducing property. Therefore, there is an advantage that the inhibition of the oxidation reaction of the metal oxide film 202 can be prevented.

In addition, since the HSG film or the like is used as the lower electrode layer 200, as shown in FIG. 4, the surface area of the dielectric layer 20 at the electrode interface is significantly increased as compared with the case where the HSG film is not used. There is. Therefore, the area A in the relationship represented by the above formula (1) becomes sufficiently large, and the effective dielectric constant can be increased, so that the capacitance of the capacitor member 2 can be further increased.

The present invention is not limited to the above-described embodiment, and for example, the capacitor member 2 is M
The structure is not limited to the IS structure and may have a SIS structure or an MIM structure. In the latter case, for example, a metal such as ruthenium (Ru) or platinum (Pt) is formed as the lower electrode layer by the CVD method or the PVD method, and the dielectric layer 20 is formed thereon by the insulating film forming method according to the present invention. (The barrier layer 203 may be omitted and only the metal oxide film 206 may be formed).
On top of that, a metal such as Ru or Pt is CV as an upper electrode.
A method such as the D method or the PVD method can be performed.

The first film formed on the barrier layer 201 may be a metal film (Ta film) formed by the PVD method or the like. Furthermore, a Si film, a SiN film, or the like may be formed as the first film, and steps S53 and S54 may be performed on the first film to oxidize and crystallize, thereby forming an insulator film containing Si as a metal. Furthermore, the use (device application) of the insulating film obtained by the present invention is not limited to the capacitor that uses the function of the dielectric, but can be used for, for example, a resistor (body) or another insulating film.

Furthermore, the method of supplying water vapor onto the wafer W is not limited to the external combustion method, and water vapor may be generated in the vicinity of or immediately above the wafer W.
_The external combustion method is preferable because it is difficult or unlikely to supply ₂ gas. Furthermore, step S5
The mixing ratio of water vapor and O ₂ gas in 3 is not particularly limited and can be appropriately set.
It is not necessary to introduce ₂ gases. In addition, a film made of so-called Rugged Polysilicon may be used instead of the HSG film.

[0059]

As described above, according to the method for forming an insulator film and the method for manufacturing a capacitor member of the present invention, the process can be simplified and the frequency of transferring the member can be reduced to improve the productivity. At the same time, it is possible to prevent a decrease in productivity even when forming a thick insulator film.

[Brief description of drawings]

FIG. 1 is a flow chart showing a procedure of a preferred embodiment relating to a method of manufacturing a capacitor member of the present invention using an insulating film forming method of the present invention.

FIG. 2 is a schematic cross-sectional view showing an example of a processing device for carrying out a part of the flow shown in FIG.

3A to 3F are process diagrams schematically showing a state in which a capacitor member is manufactured according to the procedure shown in FIG.

FIG. 4 is a reference diagram showing a more detailed cross-sectional shape of a capacitor member corresponding to FIG.

[Explanation of symbols]

2 ... Capacitor member, 10 ... Processing device, 11 ... Chamber, 14 ... Heating lamp part, 16 ... Gas supply system, 18 ... Gas exhaust system, 20 ... Dielectric layer, 200 ... Lower electrode layer (first
Electrode layer), 201 ... Barrier layer, 202 ... Metal oxide film (first film), 204 ... Metal oxide film (second film), 206 ...
Metal oxide film (third film, insulator film), 207 ... Upper electrode layer (second electrode layer), G ... Gas, W ... Wafer (base).

Continued front page    (72) Inventor Keizo Hosoda             14-3 Shinsen, Narita-shi, Chiba Nogedaira Industrial Park               Applied Materials Japan             Within the corporation F-term (reference) 5F038 AC05 AC16 AC18 EZ16 EZ17                       EZ20                 5F058 BA11 BD01 BD05 BD10 BH02                       BH03 BJ02

Claims (7)

[Claims] 1. A method of forming an insulator film containing a metal oxide on a substrate, comprising: a first step of forming a first film containing metal atoms on the substrate; and the first film. While supplying a gas containing water vapor (H ₂ O) onto the substrate having the above, the substrate is heated to form the second film on the first film.
And a second step of modifying the second film to a third film while supplying oxygen (O ₂ ) gas onto the substrate having the second film. And a third step of reforming into an insulating film. 2. In the second step, depending on the type and thickness of the first film, or the film forming conditions of the first film, the pressure around the substrate and the heating temperature of the substrate. Or the method for forming an insulator film according to claim 1, wherein the processing time of the substrate is controlled. 3. The method for forming an insulator film according to claim 1, wherein in the second step, the pressure around the substrate is set to 66 kPa to 102 kPa. 4. The heating temperature of the substrate is 650 ° C. or lower in the second step, and the heating temperature of the substrate is 70 ° C. in the third step.
The method for forming an insulator film according to claim 1, wherein the temperature is 0 ° C. or higher. 5. In the first step, the first film containing tantalum atoms as the metal atoms is formed.
The method for forming an insulator film according to claim 1. 6. A first electrode layer forming step of forming a first electrode layer on a substrate, and a method of forming an insulator film according to claim 1 on the first electrode layer. A dielectric layer forming step of forming an insulating film by forming a dielectric layer including the insulating film, and a second electrode layer forming step of forming a second electrode layer on the dielectric layer. A method for manufacturing a provided capacitor member. 7. The method of manufacturing a capacitor member according to claim 6, further comprising a barrier layer forming step of forming a barrier layer between the first electrode layer and the dielectric layer.