JP2010199497A - Apparatus for manufacturing semiconductor device and method for manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for manufacturing a semiconductor device, the apparatus sufficiently removing impurities in a film formation atmosphere; or to provide an apparatus for manufacturing a semiconductor device, the apparatus sufficiently reducing particles produced due to a routed exhaust pipe. <P>SOLUTION: A radical generator is connected to the exhaust pipe, and radicals generated by the radical generator are used to remove contaminants in the exhaust pipe. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

The technical field relates to a semiconductor device manufacturing apparatus and a semiconductor device manufacturing method.

In the plasma CVD method, a substrate is held in a chamber to which a source gas is supplied, the source gas is excited by high-frequency energy to generate plasma of the source gas, and the substrate surface is exposed to the plasma. Is a technology to form

Known problems in the production of a semiconductor thin film by the plasma CVD method include the occurrence of film defects due to adhesion of particles and the increase in impurities due to the film formation atmosphere.

Periodic chamber cleaning is essential to prevent the generation of particles. However, it is difficult to completely prevent the generation of particles by only chamber cleaning. This is because particles can be generated from other than the chamber. Examples of the particle generation source other than the chamber include an exhaust pump in an exhaust system.

There are several approaches to the problem of particles resulting from such an exhaust system. For example, a method has been proposed in which radicals generated externally are introduced into an exhaust pump to suppress the generation of particles generated around the turbo pump (see Patent Document 1).

JP 2001-131751 A

As described above, certain techniques have been proposed from the viewpoint of preventing the generation of particles due to the exhaust system. However, the purpose of such a method is merely to suppress the generation of particles, and is not intended to remove impurities (contaminating elements) such as oxygen in the film formation atmosphere.

Further, although the plasma CVD apparatus is installed in a so-called clean room, it is not preferable to arrange an exhaust pump having a movable part in the clean room because of problems such as temperature management. For this reason, the exhaust pipe may be routed so that the exhaust pump is provided in a region where the temperature control condition is loose. In such a case, with the proposed method, it is difficult to suppress the generation of particles due to the exhaust pipe, and it is difficult to remove impurities in the film formation atmosphere.

In view of the above problems, in one embodiment of the invention disclosed in this specification and the like (including at least the specification, claims, and drawings), impurities in a film formation atmosphere can be sufficiently removed. Another object is to provide a semiconductor device manufacturing apparatus. Another object is to provide a semiconductor device manufacturing apparatus that can sufficiently reduce particles caused by exhausted exhaust pipes. Another object is to manufacture a semiconductor device having a thin film in which impurities are sufficiently reduced and generation of defects is suppressed using such a manufacturing apparatus.

One embodiment of the disclosed invention is characterized in that a radical generator is connected to an exhaust pipe, and contaminants in the exhaust pipe are removed using radicals generated by the radical generator. Here, the contaminants include various contaminants including deposits in the exhaust pipe and impurities in the film forming atmosphere.

A semiconductor device manufacturing apparatus which is one embodiment of the disclosed invention includes a chamber, a first exhaust pump connected to the chamber, an exhaust pipe connected to the first exhaust pump, and a connection to the exhaust pipe A second exhaust pump and a radical generator connected to the exhaust pipe.

In the above, it is preferable that the radical generator has a function of generating radicals for removing water in the exhaust pipe. The radical generator preferably has a function of generating fluorine radicals.

Further, in the above, a heat source for heating the exhaust pipe may be provided. The first exhaust pump is preferably a turbo pump. Note that the above-described aspect is particularly effective when the length of the exhaust pipe is 1 meter or longer, or when the exhaust system has a bent portion.

A manufacturing method of a semiconductor device which is one embodiment of the disclosed invention includes a chamber, a first exhaust pump connected to the chamber, an exhaust pipe connected to the first exhaust pump, and a connection to the exhaust pipe A radical generated by the radical generator is introduced into the exhaust pipe of a semiconductor device manufacturing apparatus having a second exhaust pump and a radical generator connected to the exhaust pipe. After removing the water, a substrate is introduced into the chamber, and a semiconductor layer is formed on the substrate.

In the above, it is preferable that the radical generated by the radical generator contains a fluorine radical. In addition, it is preferable that the exhaust pipe is heated before introducing the radical, when introducing the radical, or after introducing the radical.

In the above description, the semiconductor device manufacturing apparatus need not be interpreted as being limited to a plasma CVD apparatus. Since the feature of the above aspect is that a radical generator is connected to the exhaust pipe, the present invention can be applied to any apparatus having an exhaust system. For example, the present invention may be applied to a sputtering apparatus, a vacuum deposition apparatus, or the like.

By connecting a radical generator to the exhaust pipe, contaminants (including impurities such as water) resulting from the exhaust pipe can be reduced. In addition, even when a routed exhaust pipe is used, generation of pollutants due to this can be suppressed. Further, by manufacturing a semiconductor device using such an apparatus, a semiconductor device having a thin film in which impurities are sufficiently reduced and generation of defects is suppressed can be provided.

It is a figure explaining the manufacturing apparatus of a semiconductor device. It is a figure explaining the manufacturing apparatus of a semiconductor device. It is a figure explaining the manufacturing apparatus of a semiconductor device. It is a figure explaining the manufacturing method of a semiconductor device.

Hereinafter, embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the description of the embodiments described below, and it is obvious to those skilled in the art that modes and details can be variously changed without departing from the spirit of the invention disclosed in this specification and the like. . In addition, structures according to different embodiments can be implemented in appropriate combination. Note that in the structures of the invention described below, the same portions or portions having similar functions are denoted by the same reference numerals, and repetitive description thereof is omitted. In this specification, a semiconductor device refers to any device that can function by utilizing semiconductor characteristics.

(Embodiment 1)
In this embodiment, a semiconductor device manufacturing apparatus which is one embodiment of the disclosed invention will be described with reference to FIGS. FIG. 1 shows a plasma CVD apparatus as an example of a semiconductor device manufacturing apparatus. Note that the plasma CVD apparatus is merely an example, and one embodiment of the invention may be applied to another apparatus.

The plasma CVD apparatus shown in FIG. 1 includes at least a chamber 100, a first exhaust pump 102, a second exhaust pump 104, an exhaust pipe 106 connected to the first exhaust pump and the second exhaust pump, and an exhaust pipe 106. A radical generator 108 connected to

The chamber 100 is formed of a material such as aluminum or stainless steel (SUS). This is because the adsorptivity of contaminants to a semiconductor such as oxygen or water can be reduced by electropolishing the surface. Moreover, you may use materials, such as ceramics processed so that pores may become very few, as an internal member. In this case, it is preferable to have surface smoothness with a center line average roughness of about 3 nm or less. Of course, if this circumstance permits, the chamber 100 may be formed using other materials.

The chamber 100 has an electrode 110 and an electrode 112 therein. In the example illustrated in FIG. 1, the electrode 110 is connected to the high-frequency power source 114 and the electrode 112 is grounded; however, one embodiment of the disclosed invention is not necessarily limited to this. The connection relationship between the electrode and the power source can be changed as appropriate according to the required function. The material of the electrode 110 and the electrode 112 is not particularly limited as long as the material can withstand plasma damage. For example, an aluminum alloy (aluminum and magnesium alloy) can be used. In the case of an apparatus other than the plasma CVD apparatus, it is not necessary to limit the electrodes and the power source to the above configuration.

The chamber 100 is connected to a gas supply mechanism 116 for introducing a reaction gas. The type of gas supplied by the gas supply mechanism 116 is not particularly limited. For example, when a silicon-based thin film is formed, a mechanism that can supply a gas containing silicon as a constituent element such as silane is used. It is preferable.

The first exhaust pump 102 has a function of reducing the pressure in the chamber 100. From the viewpoint of improving the productivity of the semiconductor device and reducing contaminants in the film formation atmosphere, it is preferable that the exhaust capability of the first exhaust pump 102 is high to some extent. For example, the first exhaust pump 102 may be an exhaust pump having an exhaust capability of 10 l / sec or more. An example of such an exhaust pump is a turbo pump (or turbo molecular pump: TMP). Of course, the first exhaust pump 102 is not limited to this, and various exhaust pumps can be used. In addition, the exhaust capacity of the first exhaust pump 102 is not limited to the above-described one, and can be appropriately changed according to the volume of the chamber 100.

The configuration of the second exhaust pump 104 is not particularly limited, but the second exhaust pump 104 has a function of maintaining the atmosphere in the exhaust pipe 106 connecting the first exhaust pump 102 and the second exhaust pump 104 under reduced pressure. Is preferred. Further, it is more preferable that the pressure (negative pressure) on the exhaust side of the first exhaust pump 102 has a function of making it constant or less. For example, a mechanical pump (mechanical booster pump: MBP) and a dry pump (DP) can be combined and used as the second exhaust pump 104. Of course, the second exhaust pump 104 is not limited to this, and various exhaust pumps can be used.

A radical generator 108 is connected to an exhaust pipe 106 that connects the first exhaust pump 102 and the second exhaust pump 104. Here, the reason why the radical generator is connected to the exhaust pipe 106 is to suppress the generation of pollutants caused by the exhaust pipe 106 in particular.

Contaminants that can be generated from the exhaust pipe 106 include pollutants having a certain size (referred to as macro pollutants) and pollutants having an atomic level (referred to as micro pollutants). . Examples of macro pollutants include particles resulting from peeling of deposits deposited in the film forming process. Examples of micro pollutants include oxygen resulting from evaporation of water adhering to the exhaust pipe.

Usually, the removal of micro contaminants at the time of film formation is realized by continuously flowing a gas (for example, nitrogen) that is less likely to become a contaminant to the semiconductor to the chamber. However, such means has a limit in removing contaminants in the atmosphere. This is considered to be caused by the atmospheric component flowing backward from the exhaust pipe to the chamber due to the difference between the atmospheric pressure in the chamber and the exhaust pipe, and contaminants entering the chamber.

The present inventors paid attention to this point and realized the removal of micro pollutants in the film forming atmosphere by positively removing atmospheric components in the exhaust pipe. That is, radicals generated by the radical generator 108 were introduced into the exhaust pipe 106 to clean the atmosphere in the exhaust pipe 106. Here, the type of radical is not particularly limited. However, when a fluorine radical is used, it is preferable because the above-mentioned micro contaminants can be sufficiently removed.

Note that the above-described radicals can be used to etch away substances deposited in the exhaust pipe 106. That is, macro pollutants caused by the exhaust pipe 106 can also be removed. In this regard, one embodiment of the disclosed invention is particularly effective when the exhaust pipe 106 is routed relatively long. Specifically, it is particularly effective when the length of the exhaust pipe is 1 m or longer. Since the etching performance by radicals decreases as the exhaust pipe 106 becomes longer, it is important to connect a radical generator directly to the exhaust pipe 106 in order to clean the entire exhaust pipe 106. Similarly, in the case where a bent portion (a bent portion, a portion in which a flow stagnates, etc.) exists in the exhaust system (particularly, the exhaust system closer to the chamber 100 than the exhaust pipe 106), one embodiment of the disclosed invention is effective. is there. This is because, at the bent portion, the probability that radicals change into molecules increases, and the subsequent contaminant removal performance decreases. In the case where the exhaust pipe 106 exceeding a predetermined length or the exhaust pipe 106 having a large number of bent portions is used, even if a radical generator is directly connected to the exhaust pipe 106, contaminant removal is performed. The effect of may decrease. In such a case, a plurality of radical generators may be connected to the exhaust pipe 106.

The exhaust pipe 106 is formed of a material such as stainless steel (SUS). This is because it is necessary to ensure workability and strength. Of course, as long as this circumstance permits, the exhaust pipe 106 may be formed using other materials.

The method of using the radical generator 108 is not particularly limited. For example, it is possible to operate only in the cleaning process to remove the contaminants in the exhaust pipe 106, or to always operate in the film forming process to remove the contaminants in the exhaust pipe 106 and to exhaust the exhaust. It is also possible to prevent contaminants from adhering to the tube 106.

The radical generator 108 is connected to a gas supply mechanism 118 for introducing a gas that is a raw material of the radical. The gas supplied by the gas supply mechanism 118 is not particularly limited as long as the target radical can be generated. In order to generate a fluorine radical, for example, a gas such as NF ₃ , COF ₂ , C ₂ F ₆ , CF ₄ , SF ₆ may be used. Alternatively, hydrogen radicals may be generated using water vapor or the like. Thus, when generating radicals using raw materials other than gas, the gas supply mechanism 118 only needs to supply radical raw materials. In this sense, the gas supply mechanism 118 is not limited to the designation.

As shown in this embodiment mode, a contaminant (including impurities such as water) caused by the exhaust pipe can be reduced by connecting a radical generator to the exhaust pipe. In addition, even when a routed exhaust pipe is used, generation of pollutants due to this can be suppressed. Accordingly, since the manufacturing atmosphere of the semiconductor device can be sufficiently cleaned, it is possible to provide a semiconductor device in which impurities are sufficiently reduced and generation of defects is suppressed.

Note that although a plasma CVD apparatus is described as an example of a semiconductor device manufacturing apparatus in this embodiment, one embodiment of the disclosed invention is not limited thereto. The feature of the above aspect is that the radical generator is connected to the exhaust pipe (particularly, the exhaust pipe existing between the exhaust pump and the exhaust pump), so any device having an exhaust system can be used. It can also be applied to. For example, the present invention may be applied to a sputtering apparatus, a vacuum deposition apparatus, or the like.

(Embodiment 2)
In this embodiment, a semiconductor device manufacturing apparatus which is one embodiment of the disclosed invention will be described with reference to FIGS. FIG. 2 shows a modification of the plasma CVD apparatus shown in the above embodiment.

The plasma CVD apparatus shown in FIG. 2 is connected to a chamber 100, a first exhaust pump 102, a second exhaust pump 104, an exhaust pipe 106 connected to the first exhaust pump and the second exhaust pump, and an exhaust pipe 106. The radical generator 108 is included. The exhaust pipe 106 is provided with a heating mechanism 200. That is, one of the differences between the plasma CVD apparatus described in the above embodiment and the plasma CVD apparatus described in this embodiment is the presence or absence of the heating mechanism 200. The details of the chamber 100, the first exhaust pump 102, the second exhaust pump 104, the exhaust pipe 106, the radical generator 108, and the like can be referred to the previous embodiment, and thus the description thereof is omitted here. .

The heating mechanism 200 is not particularly limited as long as it can heat the exhaust pipe 106. For example, an electric heater that generates heat by an electric current can be used. More specifically, for example, a configuration in which a resistance heating body such as a heating wire is embedded in an insulating material such as rubber or silicone and disposed on the outer periphery of the exhaust pipe 106 can be employed. Alternatively, an electric heater may be disposed inside the exhaust pipe 106.

With such a heating mechanism 200, the effect of one embodiment of the disclosed invention can be made more remarkable. That is, by having the heating mechanism 200, the effect of removing contaminants by heat and the effect of removing contaminants by radicals can be obtained together. Furthermore, by introducing the radicals after heating the exhaust pipe 106 with heat to easily remove the contaminants, the effect of removing the contaminants by radicals can be further enhanced. These effects can be said to be effects that cannot be obtained when only a radical generator is provided.

In addition, by having the heating mechanism 200 as described above, the effect of removing contaminants by radicals can be enhanced, so that the exhaust pipe 106 can be made longer. That is, the degree of freedom related to the arrangement of the apparatus can be further increased.

Note that the method of using the heating mechanism 200 is not particularly limited. For example, it is possible to remove the contaminants in the exhaust pipe 106 by operating in the cleaning process, and to remove the contaminants in the exhaust pipe 106 by always operating in the film forming process. It is also possible to prevent contaminants from adhering to 106. In any case, it can be said that the effect produced by the combination with the radical generator further improves the effect of removing contaminants by the radical generator and is useful.

The structure described in this embodiment can be combined as appropriate with any of the structures described in the other embodiments.

(Embodiment 3)
In this embodiment, a semiconductor device manufacturing apparatus which is one embodiment of the disclosed invention will be described with reference to FIGS. FIG. 3 shows a modification of the plasma CVD apparatus shown in the above embodiment.

The plasma CVD apparatus shown in FIG. 3 is connected to a chamber 100, a first exhaust pump 102, a second exhaust pump 104, an exhaust pipe 106 connected to the first exhaust pump and the second exhaust pump, and an exhaust pipe 106. The radical generator 108 is included. Further, an exhaust pipe 300 for connecting the chamber 100 and the radical generator 108 is provided. That is, one of the differences between the plasma CVD apparatus described in the previous embodiment and the plasma CVD apparatus described in this embodiment is the presence or absence of the exhaust pipe 300. The details of the chamber 100, the first exhaust pump 102, the second exhaust pump 104, the exhaust pipe 106, the radical generator 108, and the like can be referred to the previous embodiment, and thus the description thereof is omitted here. .

Note that in this embodiment, the heating mechanism 200 described in the above embodiment is not provided. However, one embodiment of the disclosed invention is not limited to this. A configuration in which the heating mechanism 200 is also provided may be employed.

The material of the exhaust pipe 300 can be the same as that of the exhaust pipe 106. For example, a material such as stainless steel (SUS) can be used. This is because there is a demand for workability and strength as in the case of the exhaust pipe 106. Needless to say, other materials may be used as long as this circumstance permits.

By having such an exhaust pipe 300, contaminants in the exhaust pipe 106 can be removed using radicals generated outside, and at the same time, the inside of the chamber 100 can be cleaned. This makes it possible to more efficiently clean the chamber 100 and remove contaminants in the exhaust pipe 106.

Note that the timing of cleaning the chamber 100 is not particularly limited. For example, cleaning may be performed for each film forming process, or cleaning may be performed after the film forming process is performed a predetermined number of times. In addition, it is preferable that the cleaning process of the chamber 100 and the removal process of the contaminant in the exhaust pipe 106 are performed separately, but they may be performed simultaneously.

The structure described in this embodiment can be combined as appropriate with any of the structures described in the other embodiments.

(Embodiment 4)
In this embodiment, a method for manufacturing a thin film transistor will be described with reference to FIGS. 4A to 4C as an example of a method for manufacturing a semiconductor device using the semiconductor device manufacturing apparatus which is one embodiment of the disclosed invention.

First, the substrate 400 is prepared (see FIG. 4A). There is no particular limitation on a substrate that can be used, but at least heat resistance enough to withstand heat treatment performed later is required. For example, when a glass substrate is used as the substrate 400, a substrate having a strain point of 500 ° C. or higher is preferably used. Glass materials such as aluminosilicate glass, aluminoborosilicate glass, and barium borosilicate glass are usually used for the glass substrate.

Note that a substrate formed of an insulator such as a ceramic substrate, a quartz substrate, or a sapphire substrate may be used instead of the glass substrate. In addition, crystallized glass or the like can be used. Alternatively, a semiconductor substrate such as a silicon substrate may be coated with an insulating material, or a metal substrate made of a metal material may be coated with an insulating material. A plastic substrate or the like can be used as long as it can withstand the heat treatment in the manufacturing process.

Note that although not illustrated in FIG. 4, an insulating layer serving as a base may be formed over the substrate 400. By providing such an insulating layer, even when an impurity (such as an alkali metal or an alkaline earth metal) is contained in the substrate 400, the impurity can be prevented from diffusing into the semiconductor layer. The insulating layer may have a single layer structure or a stacked structure. Examples of the material forming the insulating layer include silicon oxide, silicon nitride, silicon oxynitride, and silicon nitride oxide. Alternatively, a material in which a halogen element such as fluorine or chlorine is added to the above insulating material (silicon oxide or the like) may be used. In this case, since the impurity is fixed by the halogen element, the impurity can be prevented from diffusing into the semiconductor layer.

Note that in this specification and the like, the term “oxynitride” refers to a composition whose oxygen content (number of atoms) is higher than that of nitrogen. For example, silicon oxynitride refers to oxygen at 50 atomic% or more and 70 It includes atoms in a range of not more than atomic%, nitrogen not less than 0.5 atom% and not more than 15 atom%, silicon not less than 25 atom% and not more than 35 atom%, and hydrogen not less than 0.1 atom% and not more than 10 atom%. In addition, a nitrided oxide indicates a composition whose nitrogen content (number of atoms) is higher than that of oxygen. For example, silicon nitride oxide refers to an oxygen content of 5 atomic% to 30 atomic% and nitrogen content. It includes 20 atomic% to 55 atomic%, silicon 25 atomic% to 35 atomic%, and hydrogen 10 atomic% to 25 atomic%. However, the above range is measured using Rutherford Backscattering Spectrometry (RBS) or Hydrogen Forward Scattering (HFS). Further, the total content ratio of the constituent elements does not exceed 100 atomic%.

Next, a gate electrode layer 402 is formed over the substrate 400, and a gate insulating layer 404 is formed so as to cover the gate electrode layer 402 (see FIG. 4B).

The gate electrode layer 402 can be formed by forming a conductive layer over the entire surface of the substrate 400 and then etching the conductive layer using a photolithography method. Here, the gate electrode layer 402 may include other electrodes and wirings formed of the conductive layer, such as a gate wiring.

When the gate electrode layer 402 is formed, etching is performed so that an end portion of the gate electrode layer 402 has a tapered shape in order to improve coverage with a gate insulating layer 404 to be formed later and prevent disconnection. . For example, it is preferable that the taper angle is 20 ° or more and less than 90 °. Here, the “taper angle” refers to a side surface and a bottom surface of a layer having a tapered shape (here, the gate electrode layer 402) when observed from a cross-sectional direction (a surface orthogonal to the surface of the substrate 400). The inclination angle made by. That is, here, the angle of the lower end portion of the gate electrode layer 402 when observed from the cross-sectional direction is referred to.

The gate electrode layer 402 is preferably formed using a conductive material such as aluminum (Al), copper (Cu), molybdenum (Mo), tungsten (W), or titanium (Ti). Note that when aluminum is used for the wiring or the electrode, it is preferable to form the aluminum alone in combination with a heat resistant conductive material because aluminum alone has low heat resistance and is easily corroded.

The heat-resistant conductive material includes an element selected from titanium (Ti), tantalum (Ta), tungsten (W), molybdenum (Mo), chromium (Cr), Nd (neodymium), and scandium (Sc). Examples thereof include a metal containing, an alloy containing the above-described element as a component, an alloy combining the above-described elements, and a nitride containing the above-described element as a component. A wiring or an electrode may be formed by stacking these heat-resistant conductive materials and aluminum (or copper).

Note that the gate electrode layer 402 can be selectively formed over the substrate 400 by a droplet discharge method, a screen printing method, or the like.

The gate insulating layer 404 can be formed using a material such as silicon oxide, silicon oxynitride, silicon nitride, silicon nitride oxide, aluminum oxide, or tantalum oxide. Alternatively, films formed using these materials may be stacked. These films are preferably formed to have a thickness of 50 nm to 250 nm by a sputtering method or the like. For example, a silicon oxide film with a thickness of 100 nm can be formed as the gate insulating layer 404 by a sputtering method. As the sputtering apparatus, as described in the above embodiment, an apparatus including a radical generator in an exhaust pipe is preferably used; however, one embodiment of the disclosed invention is not limited thereto.

Next, a semiconductor layer 406 and a semiconductor layer 408 to which an impurity element imparting one conductivity type is added are formed in order over the gate insulating layer 404 (see FIG. 4C).

The semiconductor layer 406 can be formed using various semiconductor materials such as silicon, germanium, an oxide semiconductor, and an organic semiconductor. Here, the case where microcrystalline silicon is used for the semiconductor layer 406 is described as an example.

Microcrystalline silicon is a semiconductor having an intermediate structure between amorphous silicon and crystalline silicon (including single crystal and polycrystal), and has a crystal grain size of approximately 2 nm to 100 nm. Microcrystalline silicon has its Raman spectrum peak shifted to a lower wave number side than 521 cm ^−1, which indicates single crystal silicon. That is, the peak of the Raman spectrum of the microcrystalline silicon exists between the 480 cm ^-1 indicating the 521 cm ^-1 and the amorphous silicon which represents single crystal silicon. Further, in order to terminate dangling bonds, hydrogen or halogen may be contained by 1 atomic% or more.

The semiconductor layer 406 using microcrystalline silicon can be formed using, for example, high-frequency plasma CVD with a frequency of several tens to several hundreds of MHz, or microwave plasma CVD with a frequency of 1 GHz or more. As the source gas, a silicon compound typified by SiH ₄ , Si ₂ H ₆ , SiH ₂ Cl ₂ , SiHCl ₃ , SiCl ₄ , SiF ₄ or the like diluted with hydrogen can be used. One or more kinds of rare gas elements selected from helium, argon, krypton, and neon may be added to the aforementioned silicon compound or hydrogen. Note that the thickness of the semiconductor layer 406 is 2 nm to 50 nm, preferably 10 nm to 30 nm.

Here, as the plasma CVD apparatus, the plasma CVD apparatus described in the above embodiment is preferably used. Accordingly, contaminants such as oxygen in the deposition atmosphere can be sufficiently removed, so that a high-quality semiconductor layer 406 can be obtained. In addition, the occurrence of film defects due to the generation of particles can be sufficiently suppressed. In addition, since disassembly cleaning for exhaust pipe cleaning is not required, the productivity of the semiconductor device can be improved.

The semiconductor layer 408 can be formed in a manner similar to that of the semiconductor layer 406. Here, in the case of forming an n-channel thin film transistor, for example, phosphorus can be used as an impurity element to be added. In the case of forming a p-channel thin film transistor, for example, boron can be used as an impurity element to be added. The semiconductor layer 408 may be formed to have a thickness of about 2 nm to 50 nm (preferably 10 nm to 30 nm). As a manufacturing method, a plasma CVD method in which a gas containing the above impurity element (for example, PH ₃ or B ₂ H ₆ ) is added to a source gas can be used.

Here too, it is preferable to use the plasma CVD apparatus described in the above embodiment; however, one embodiment of the disclosed invention is not limited thereto.

Next, a mask is selectively formed over the semiconductor layer 408, and the semiconductor layer 406 and the semiconductor layer 408 are etched using the mask to form the island-shaped semiconductor layer 410 and the island-shaped semiconductor layer 412 (see FIG. (See FIG. 4D).

Then, the source electrode layer 414 and the drain electrode layer 416 which are electrically connected to the island-shaped semiconductor layer 410 and the island-shaped semiconductor layer 412 are formed (see FIG. 4B). Note that the function of the source electrode or the drain electrode (source wiring or drain wiring) may be changed depending on the usage mode of the thin film transistor. For this reason, the function of an electrode (or wiring) is not interpreted as being limited to the above designation. Further, the source electrode layer 414 and the drain electrode layer 416 may include other electrodes and wirings formed of the conductive layer, such as source wirings and power supply lines.

The source electrode layer 414 and the drain electrode layer 416 can be formed by forming a conductive layer over the entire surface and then etching the conductive layer using a photolithography method. Note that it is preferable that at least part of the island-shaped semiconductor layer 412 be etched together. Accordingly, the island-shaped semiconductor layer 418 and the island-shaped semiconductor layer 420 can be formed. Note that in this embodiment, the case where part of the island-shaped semiconductor layer 410 is removed in the above etching is described; however, one embodiment of the disclosed invention is not construed as being limited thereto. . A predetermined insulating layer may be provided between the island-shaped semiconductor layer 410 and the island-shaped semiconductor layer 412 so that the island-shaped semiconductor layer 410 is not etched.

The source electrode layer 414 and the drain electrode layer 416 are preferably formed using a conductive material such as aluminum (Al), copper (Cu), molybdenum (Mo), tungsten (W), or titanium (Ti). Note that when aluminum is used for the wiring or the electrode, it is preferable to form the aluminum alone in combination with a heat resistant conductive material because aluminum alone has low heat resistance and is easily corroded.

The heat-resistant conductive material includes an element selected from titanium (Ti), tantalum (Ta), tungsten (W), molybdenum (Mo), chromium (Cr), Nd (neodymium), and scandium (Sc). Examples thereof include a metal containing, an alloy containing the above-described element as a component, an alloy combining the above-described elements, and a nitride containing the above-described element as a component. A wiring or an electrode may be formed by stacking these heat-resistant conductive materials and aluminum (or copper).

Note that the source electrode layer 414 and the drain electrode layer 416 can be selectively formed by a droplet discharge method, a screen printing method, or the like. In this case, a separate step of etching the island-shaped semiconductor layer 412 is necessary.

Through the above process, a thin film transistor can be manufactured.

In this embodiment, when the semiconductor layer 406 is formed, the semiconductor device manufacturing apparatus described in the above embodiment is used. Accordingly, contaminants such as oxygen in the film formation atmosphere can be sufficiently removed, so that a semiconductor device including a high-quality semiconductor layer can be obtained. In addition, since the generation of film defects due to the generation of particles can be sufficiently suppressed, the yield of semiconductor devices is improved. In addition, since disassembly cleaning for exhaust pipe cleaning is not required, the productivity of the semiconductor device can be improved.

Note that in this embodiment, the above semiconductor device manufacturing apparatus is used particularly when the semiconductor layer 406 is formed; however, one embodiment of the disclosed invention is not construed as being limited thereto. In the process of using a semiconductor device manufacturing apparatus having an exhaust system, the semiconductor device manufacturing apparatus described above can be used as appropriate.

The structure described in this embodiment can be combined as appropriate with any of the structures described in the other embodiments.

100 chamber 102 first exhaust pump 104 second exhaust pump 106 exhaust pipe 108 radical generator 110 electrode 112 electrode 114 high frequency power supply 116 gas supply mechanism 118 gas supply mechanism 200 heating mechanism 300 exhaust pipe 400 substrate 402 gate electrode layer 404 gate Insulating layer 406 Semiconductor layer 408 Semiconductor layer 410 Island-like semiconductor layer 412 Island-like semiconductor layer 414 Source electrode layer 416 Drain electrode layer 418 Island-like semiconductor layer 420 Island-like semiconductor layer

Claims (8)

A chamber;
A first exhaust pump connected to the chamber;
An exhaust pipe connected to the first exhaust pump;
A second exhaust pump connected to the exhaust pipe;
And a radical generator connected to the exhaust pipe. In claim 1,
The said radical generator has a function which generates the radical for removing the water in the said exhaust pipe, The manufacturing apparatus of the semiconductor device characterized by the above-mentioned. In claim 1 or claim 2,
The radical generator has a function of generating fluorine radicals, and is a semiconductor device manufacturing apparatus. In any one of Claim 1 thru | or 3,
An apparatus for manufacturing a semiconductor device, comprising: a heat source for heating the exhaust pipe. In any one of Claims 1 thru | or 4,
The semiconductor device manufacturing apparatus, wherein the first exhaust pump is a turbo pump. A chamber, a first exhaust pump connected to the chamber, an exhaust pipe connected to the first exhaust pump, a second exhaust pump connected to the exhaust pipe, and the exhaust pipe. After introducing radicals generated by the radical generator into the exhaust pipe of the semiconductor device manufacturing apparatus having a radical generator, and removing water in the exhaust pipe,
Introducing a substrate into the chamber;
A method for manufacturing a semiconductor device, comprising forming a semiconductor layer on the substrate. In claim 6,
The radical generated by the radical generator contains a fluorine radical. In claim 6 or claim 7,
A method for manufacturing a semiconductor device, comprising: heating the exhaust pipe before introducing the radical, when introducing the radical, or after introducing the radical.

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