JP2010065296A - Method and apparatus for continuously depositing thin film, film-deposited glass substrate, and semi-conductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus capable of continuously depositing various kinds of thin films on a substrate at high speed, and to provide a film-deposited glass substrate and a semi-conductor device. <P>SOLUTION: A first feed port 131 for feeding first reactive gas 11 and a first exhaust port 135 for exhausting the first reactive gas are provided in a nucleus formation zone 115. A second feed port 132 for feeding second reactive gas 12 and a second exhaust port 136 for exhausting the second reactive gas are provided in a crystal growth zone 116. Favorable reactive gases of different kinds can be used for the first reactive gas 11 to be used for nucleus formation, and for the second reactive gas to be used for crystal growth. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technique such as a continuous thin film forming method for continuously forming a predetermined thin film on a strip-shaped substrate having a small thickness with respect to the width and sufficiently long in the longitudinal direction, and in particular, amorphous silicon or polycrystalline The present invention relates to a technique such as a continuous thin film forming method suitable for forming a dense silicon thin film such as silicon (polysilicon).

  In TFT (Thin Film Transistor), organic EL, etc., a silicon thin film is formed on a glass substrate, and a drive circuit is formed on the formed silicon thin film. Film formation technology for forming various thin films on such a glass substrate is an important technical field that is the basis of semiconductor manufacturing technology.

  As an example of a technique for forming a film on a glass substrate, a film forming process of a TFT or the like will be described. In the TFT manufacturing process, an amorphous silicon film or a polysilicon film is formed on a glass substrate, and a driving circuit for driving a liquid crystal or a semiconductor control circuit such as a transistor is formed on the silicon film. As a recent trend, a technique for forming a polysilicon thin film on a glass substrate has attracted attention because of a demand for high-speed operation. In the conventional technology for forming a polysilicon film, first, after amorphous silicon is formed, the amorphous silicon is converted into polysilicon by laser annealing or thermal annealing.

Usually, vapor deposition, sputtering, or various CVD methods are used to form amorphous silicon on a glass substrate. In the most frequently used plasma CVD method, silane (SiH ₄ ) and disilane (Si ₂ H ₆ ) as source gases are decomposed by glow discharge, and an amorphous silicon thin film is grown on a substrate. For the substrate, crystalline silicon, glass, heat-resistant plastic or the like is used, and it is usually grown at 400 ° C. or lower. In addition, this method has an advantage that a large area can be created.

  An example of a conventional technique for forming a polysilicon film on a glass substrate will be described with reference to Patent Document 1. First, an oxide film is formed on a glass substrate to be a substrate, and a hydrogen-containing amorphous silicon film is deposited thereon by a CVD method or the like. Thereafter, dehydrogenation treatment is performed by heat treatment, and the amorphous silicon film is changed to a polysilicon film by annealing treatment by excimer laser irradiation. Thereafter, a polysilicon film can be obtained through some further processing.

  The hydrogen-containing amorphous silicon film as described above is generally deposited by a CVD method or a plasma CVD method. Such a process such as a CVD method, a plasma CVD method, or a plasma method is usually performed at a temperature of about 400 ° C., and a dehydrogenation process is also usually performed at a temperature of 400 to 500 ° C. for about 60 minutes.

As described above, since the conventional process for forming a polysilicon film is performed at about 500 ° C. at the maximum, multi-component glass or the like having a low material cost can be used as a substrate material, and the degree of freedom in selecting a substrate material is increased. There is an advantage of high.
JP-A-11-204794

  However, the film formation process using silane or the like as a raw material is a batch process because it involves a decompression process, and it is not possible to improve productivity by greatly increasing the film formation speed with existing apparatuses. Especially in the case of a vacuum process using silane, the amorphous silicon thin film contains a large amount of hydrogen. Therefore, before thermal annealing or laser annealing to increase the crystal grain size and convert it to polysilicon, Therefore, it was necessary to perform the dehydrogenation process for a long time. This dehydrogenation process has a serious problem in productivity, for example, requiring a processing time of 60 minutes.

Further, when batch processes such as nucleation, crystal growth, and annealing are performed, it takes a certain amount of time to heat to a necessary temperature in the next process using, for example, a heating furnace. For this reason, for example, crystal nuclei formed in the nucleation process may change due to migration or the like during the transition to the crystal growth process, leading to deterioration in quality.
Furthermore, although silane heretofore material gas (SiH ₄₎ or the like is used, the silane is because of the risk such easily ignited reacts with oxygen, even handling a problem difficult.

  The present invention has been made in view of the above-described problems of the prior art, and a continuous thin film forming method, a forming apparatus, a film forming glass substrate, and a film forming glass substrate capable of continuously forming various thin films on a substrate at a high speed. An object is to provide a semiconductor device.

  According to a first aspect of the continuous thin film forming method of the present invention, the substrate is formed by using a reaction tube that allows a strip-shaped substrate and a reaction gas to continuously pass through the inside, and a heating furnace that is heated from the outside of the reaction tube. A continuous thin film forming method for continuously forming a thin film comprising the reaction gas component on the reaction tube, wherein the reaction tube is divided into a nucleation zone, a crystal growth zone, and a cooling zone in a direction of passing the substrate. The first reaction gas is supplied into the nucleation zone from the first supply port provided on the inlet side in the nucleation zone and exhausted from the first exhaust port provided on the outlet side. A predetermined crystal nucleus is formed on the substrate, and a second reaction gas different from the first reaction gas is supplied to the inside of the crystal growth zone from a second supply port provided on the inlet side in the crystal growth zone. The second exhaust provided on the exit side Grown the crystal nuclei by exhausting from the mouth to form a crystal, and forming a thin film by fixing the crystals by cooling the substrate in the cooling zone.

  Another aspect of the method for forming a continuous thin film according to the present invention is characterized in that the heating furnace heats the nucleation zone, the crystal growth zone, and the cooling zone independently.

  Another aspect of the continuous thin film forming method according to the present invention is characterized in that the first reaction gas contains more chlorine component than the second reaction gas.

In another aspect of the method for forming a continuous thin film according to the present invention, the first reaction gas is a gas obtained by mixing dichlorosilane (SiH ₂ Cl ₂ ) with silicon tetrachloride (SiCl ₄ ) or chlorine (Cl ₂ ). It is characterized by that.

Another aspect of the continuous thin film forming method according to the present invention is characterized in that the second reaction gas is dichlorosilane (SiH ₂ Cl ₂ ).

  In another aspect of the method for forming a continuous thin film according to the present invention, a cooling gas is supplied from the third supply port provided on the inlet side of the cooling zone to the inside of the cooling zone, and the substrate is placed outside the reaction tube. It is characterized by exhausting from the outlet for drawing out.

Another aspect of the continuous thin film forming method according to the present invention is characterized in that the cooling gas is hydrogen (H ₂ ).

  In another aspect of the continuous thin film forming method according to the present invention, the nucleation zone is provided with a fourth supply port between the introduction port for introducing the substrate and the first supply port. A predetermined inert gas is supplied to the inside of the nucleation zone from four supply ports, and exhausted from the introduction port.

  In another aspect of the method for forming a continuous thin film according to the present invention, the substrate is temporarily cooled at a boundary portion between the nucleation zone and the crystal growth zone, and at a boundary portion between the crystal growth zone and the cooling zone. It is characterized by being.

  Another aspect of the continuous thin film forming method according to the present invention is characterized in that the thin film has a polycrystalline structure.

  Another aspect of the continuous thin film forming method according to the present invention is characterized in that the thin film is a polysilicon thin film.

  Another aspect of the continuous thin film forming method according to the present invention is characterized in that thermal CVD is used as the heating means of the heating furnace.

  Another aspect of the continuous thin film forming method according to the present invention is characterized in that plasma CVD is used as the heating means of the heating furnace.

Another aspect of the method for forming a continuous thin film according to the present invention is characterized in that quartz glass having a thickness of 30 μm to 300 μm is used as the substrate.

  According to a first aspect of the method for manufacturing a glass substrate according to the present invention, the substrate manufactured by the continuous thin film forming method according to any one of the above items is cut into a desired length and connected in the width direction. Thus, a substrate provided with the thin film is manufactured.

  According to a first aspect of the continuous thin film forming apparatus of the present invention, the substrate includes: a reaction tube that continuously passes a strip-shaped substrate and a reaction gas; and a heating furnace that is heated from the outside of the reaction tube. An apparatus for continuously forming a thin film comprising a component of the reaction gas thereon, wherein the reaction tube is divided into a nucleation zone, a crystal growth zone, and a cooling zone in a direction of passing the substrate. A first supply port provided on the inlet side of the nucleation zone for supplying a first reaction gas to the inside of the nucleation zone; and provided on an outlet side of the nucleation zone. A first exhaust port for exhausting the reaction gas, and a second supply port that is provided on the inlet side of the crystal growth zone and supplies a second reaction gas different from the first reaction gas to the inside of the crystal growth zone And exit of the crystal growth zone A second exhaust port for exhausting the second reaction gas provided, characterized in that it comprises a.

  In another aspect of the continuous thin film forming apparatus according to the present invention, the heating furnace heats the nucleation zone, a second heating unit that heats the crystal growth zone, and the cooling zone. And heating by the first to third heating units is independently controlled.

  In another aspect of the continuous thin film forming apparatus according to the present invention, the reaction tube has a cross section at the boundary between the nucleation zone and the crystal growth zone, and a cross section at the boundary between the crystal growth zone and the cooling zone. It is narrower than the cross section of each zone.

  In another aspect of the continuous thin film forming apparatus according to the present invention, a third supply port for supplying a cooling gas to the inside of the cooling zone is provided on the inlet side of the cooling zone, and the substrate is drawn out of the reaction tube. The cooling gas is exhausted from an outlet for the purpose.

  In another aspect of the continuous thin film forming apparatus according to the present invention, the nucleation zone is provided with a fourth supply port between the introduction port for introducing the substrate and the first supply port, and the fourth supply A predetermined inert gas is supplied from the mouth into the nucleation zone and exhausted from the introduction port.

  Another aspect of the continuous thin film forming apparatus according to the present invention is characterized in that a susceptor is disposed in each of the nucleation zone, the crystal growth zone, and the cooling zone in proximity to the substrate. To do.

  In another aspect of the continuous thin film forming apparatus according to the present invention, the heating furnace is configured to react the reaction at each of a boundary between the nucleation zone and the crystal growth zone and a boundary between the crystal growth zone and the cooling zone. It has the space | gap part for making a pipe | tube contact with external air, It is characterized by the above-mentioned.

  According to another aspect of the continuous thin film forming apparatus of the present invention, in the continuous thin film forming apparatus according to any one of the above, a means for supplying a belt-shaped substrate and a means for winding up the formed substrate are provided. It is characterized by being.

  A first aspect of a strip-shaped film-forming glass substrate according to the present invention is characterized by being manufactured using the continuous thin film forming apparatus according to any one of the above.

  A first aspect of the two-dimensional film-formation glass substrate according to the present invention is characterized in that it is produced by cutting the strip-form film-formation glass substrate into a desired length and connecting it in the width direction.

  A first aspect of a semiconductor element or a semiconductor module according to the present invention is characterized by being manufactured using the above-described belt-shaped film-formation glass substrate or two-dimensional film-formation glass substrate.

  According to the present invention, by using different reaction gases for nucleation and crystal growth, various thin films having a predetermined crystal grain size can be continuously formed on a substrate at high speed, and a continuous thin film forming method and apparatus It is possible to provide a film-forming glass substrate and a semiconductor element.

  A continuous thin film forming method and the like according to a preferred embodiment of the present invention will be described with reference to the drawings. In the following description, an example in which a silicon thin film is formed on a quartz glass substrate will be described as an example. However, the present invention is not limited thereto, and a predetermined thin film is formed corresponding to the type of reaction gas. Is possible. Further, the substrate is not limited to the quartz glass substrate, and various glass substrates, Pyrex (registered trademark), and the like suitable for the temperature conditions can be used.

(First embodiment)
A continuous thin film forming method and a continuous thin film forming apparatus according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic configuration diagram showing an example of the continuous thin film forming apparatus of the present embodiment. As the substrate 10 of the present embodiment, a band-shaped quartz glass substrate having a small thickness and a long length is used.

  In FIG. 1, the continuous thin film forming apparatus 100 includes a reaction tube 110, a heating furnace 120, and a supply drum 141 and a take-up drum 142 for moving the substrate 10. The substrate 10 wound around the supply drum 141 is introduced into the reaction tube 110 from the introduction port 111 of the reaction tube 110, formed into a film inside the reaction tube 110, and then drawn out from the drawing port 112 to take up the winding drum 142. Rolled up.

  A schematic configuration of the reaction tube 110 will be described below. The reaction tube 110 can be formed of quartz glass and is divided into three zones by the first boundary portion 113 and the second boundary portion 114. The first boundary portion 113 and the second boundary portion 114 are formed so as to have a cross-sectional area smaller than the cross-sectional area of the nearby reaction tube 110. As a result, the gas supplied to each zone is prevented from entering the adjacent zones as much as possible.

  The reaction tube 110 has a nucleation zone 115 from the inlet 111 to the first boundary 113, a crystal growth zone 116 from the first boundary 113 to the second boundary 114, and from the second boundary 114 to the outlet 112. Is a cooling zone 117. Each zone is penetrated so that the substrate 10 can move from the inlet 111 to the outlet 112 through the nucleation zone 115, the crystal growth zone 116, and the cooling zone 117.

  The nucleation zone 115 is provided with a first supply port 131 and a fourth supply port 134 for supplying a predetermined gas, and a first exhaust port 135 for exhausting the gas. The first supply port 131 and the first exhaust port 135 are provided on the inlet side (inlet port 111 side) and outlet side (first boundary portion 113 side) of the nucleation zone 115, respectively, and are supplied from the first supply port 131. The first reaction gas 11 is exhausted from the first exhaust port 135.

  The fourth supply port 134 is provided between the introduction port 111 and the first supply port 131, and the inert gas 13 is supplied into the nucleation zone 115 via this. The inert gas 13 supplied from the fourth supply port 134 is supplied to prevent the first reaction gas 11 supplied from the first supply port 131 from leaking out from the introduction port 111 side. The first reaction gas 11 is shielded and exhausted from the introduction port 111 to the outside. For example, argon (Ar) gas can be used as the inert gas 13.

  The crystal growth zone 116 is provided with a second supply port 132 for supplying the second reaction gas 12 and a second exhaust port 136 for exhausting the second reaction gas 12. The second supply port 132 and the second exhaust port 136 are provided on the inlet side (first boundary portion 113 side) and the outlet side (second boundary portion 114 side) of the crystal growth zone 116, respectively. The supplied second reaction gas 12 is exhausted from the second exhaust port 136.

Further, the cooling zone 117 is provided with a third supply port 133 for supplying the cooling gas 14 to the inside thereof. The cooling gas 14 cools the substrate 10 and prevents the second reaction gas 12 from flowing from the crystal growth zone 116. The third supply port 133 is provided on the inlet side (second boundary portion 114 side) of the cooling zone 117, and exhausts the cooling gas 14 supplied from the third supply port 133 from the outlet 112. For example, hydrogen (H ₂ ) gas or helium (He ₂ ) gas can be used as the cooling gas 14.

  Next, the configuration of the heating furnace 120 will be described below. The heating furnace 120 is arranged on the outer periphery of the reaction tube 110 and is configured to heat the inside of the reaction tube 110 independently for each of the nucleation zone 115, the crystal growth zone 116, and the cooling zone 117. That is, a first heating unit 121 that heats the nucleation zone 115, a second heating unit 122 that heats the crystal growth zone 116, and a third heating unit 123 that heats the cooling zone 117 are provided inside the furnace shell 120 a. It has been. The first to third heating units 121 to 123 are independently controlled by the temperature control unit 124, and can heat the nucleation zone 115, the crystal growth zone 116, and the cooling zone 117 independently.

  Thermal CVD can be used as a heating means of the heating furnace 120. In this case, infrared rays are emitted from the first to third heating units 121 to 123. In order to heat the substrate 10 to a high temperature by infrared rays, susceptors 125 to 127 are arranged in each zone inside the reaction furnace 110 in proximity to or in contact with the substrate. The heating means of the heating furnace 120 is not limited to thermal CVD, and for example, plasma CVD or the like can be used.

In the continuous thin film forming apparatus 100 configured as described above, the thin film is formed while the substrate 10 wound around the supply drum 141 is introduced into the reaction tube 110 from the inlet 111 and passes through the zones 115 to 117. Then, it is drawn out from the outlet 112 and taken up on the take-up drum 142. Dimension b so that bd / (2 (b + d)) is not less than 0.015 and not more than 0.15, where b is the width and d is the thickness of the cross section of the surface perpendicular to the longitudinal direction of substrate 10. , D should be determined. This makes it possible to form polysilicon.

  As a specific example of the substrate 10, it is preferable to use a substrate which is processed into a long band shape having a width b of several mm to several tens mm and a thickness d of 30 μm to 300 μm. Thereby, the heat capacity of the substrate 10 can be reduced. Preferably, the thickness d is 60 μm or more and 200 μm or less. Thereby, flexibility increases and handling becomes easy. At the same time, by increasing the surface area, the substrate 10 can be rapidly heated and cooled rapidly, and a thin film can be formed on the substrate 10 continuously at high speed. When a quartz glass substrate is used as the substrate 10, it can be heated to 1200 ° C. or more by using thermal CVD for the heating furnace 120. As a result, a silicon thin film having a thickness of about 30 nm to 500 nm can be formed on the substrate 10.

  The substrate 10 is heated to a predetermined temperature while passing through the nucleation zone 115, and crystal nuclei composed of components of the first reaction gas 11 supplied from the first supply part 131 are formed on the surface thereof. In the present embodiment, the first reaction gas 11 is a mixture of a gas that is a raw material for crystal nuclei and a gas containing a large amount of chlorine. Chlorine has an etching effect for scraping off crystal nuclei formed on the substrate 10 (hereinafter, such a gas is referred to as an etching gas), and is formed on the substrate 10 by mixing such a gas. The number of crystal nuclei to be limited is limited.

As an example of the first reaction gas 11, a mixture of dichlorosilane (SiH ₂ Cl ₂ ) and an etching gas containing a large amount of chlorine such as silicon tetrachloride (SiCl ₄ ) or chlorine (Cl ₂ ) can be used. Thus, silicon (silicon) crystal nuclei are formed on the substrate 10. By mixing the etching gas, the number of silicon crystal nuclei remaining on the substrate 10 can be limited. The number of crystal nuclei remaining on the substrate 10 decreases as the ratio of the etching gas mixed into the first reaction gas 11 increases.

  As described above, in this embodiment, the formation state of crystal nuclei can be controlled by the mixing ratio of the etching gas. The distribution state of crystal nuclei formed on the substrate 10 can also be changed by changing the type of gas used for the first reaction gas 11. Furthermore, the number of crystal nuclei can also be adjusted by the supply amount of the first reaction gas 11, and the supply amount of the first reaction gas 11 is controlled using the gas flow rate control unit 130 shown in FIG. When the number of crystal nuclei formed on the substrate 10 is reduced, the supply amount of the first reaction gas 11 is also reduced.

  In the next crystal growth zone 116, the substrate 10 is further heated than the nucleation zone 115, and the second reaction gas 12 supplied from the second supply unit 132 is decomposed on the substrate 10 to grow Si crystals. In the crystal growth zone 116, the substrate 10 is preferably heated in the range of 1050 ° C. to 1300 ° C.

As the second reaction gas 12, it is preferable to use a relatively stable and safe gas having a smaller constituent chlorine component than the first reaction gas 11. Further, when the number of crystal nuclei formed in the nucleation zone 115 is limited, each crystal nuclei can be grown to a large extent. Therefore, a large amount of the second reaction gas 12 is supplied to the crystal growth zone 116. Good. As the second reaction gas 12, dichlorosilane (SiH ₂ Cl ₂ ) can be used. Silane (SiH ₄ ) or the like can also be used, but silane (SiH ₄ ), disilane (Si ₂ H ₆ ) and the like are not necessarily preferable because they easily ignite and require attention in handling.

In the subsequent cooling zone 117, the silicon crystal grains formed in the crystal growth zone 116 are rapidly cooled here. In the present embodiment, the cooling by supplying a cooling gas (H ₂ gas) to the cooling zone 117, the crystal grains are allowed to settle on the substrate 10 to suppress for migration on the substrate 10 by this .

  As in the above example, in this embodiment, by appropriately selecting the respective types of the first reaction gas 11 supplied to the nucleation zone 115 and the second reaction gas 12 supplied to the crystal growth zone 116, A thin film made of relatively large crystal grains can be formed on the substrate 10. In the present embodiment, different types of gases can be used for the first reaction gas 11 for forming crystal nuclei and the second reaction gas 12 for crystal growth. Thereby, the distribution of crystal nuclei can be suitably adjusted, and the crystal can be grown so as to be almost uniform in a desired size.

In order to form a crystal having a large particle size as in the above embodiment, a mixture of dichlorosilane (SiH ₂ Cl ₂ ) and an etching gas containing a large amount of chlorine component is used as the first reaction gas 11. In this way, the number of crystal nuclei generated in the nucleation zone 115 is reduced, and each crystal nuclei can be grown large in the crystal growth zone 116 using a second reaction gas having a low mixing ratio of etching gas. it can. On the other hand, when a crystal having a small particle size is formed, it is preferable to use a silane-based gas that does not contain chlorine or a low mixing ratio of the etching gas as the first reaction gas 11. As a result, the number of crystal nuclei generated in the nucleation zone 115 can be increased and the interval between crystal nuclei can be reduced.

  In the continuous thin film forming apparatus 100, a gas flow rate control unit 130 is provided to adjust the flow rates or gas pressures of the first reaction gas 11, the second reaction gas 12, the inert gas 13, and the cooling gas 14. ing. The gas flow rate control unit 130 can independently control the flow rate or gas pressure of each gas, thereby adjusting the supply amounts of the first reaction gas 11 and the second reaction gas 12. Thus, the distribution state of crystal nuclei and crystal growth can be adjusted.

  Next, an example of the temperature distribution realized in the reaction tube 110 in the continuous thin film forming apparatus 100 of the present embodiment will be described with reference to FIG. In FIG. 2, the temperature change of the substrate 10 is indicated by reference numeral 20, and the temperature distribution inside the reaction tube 110 is indicated by reference numeral 21. In the present embodiment, the length of the boundary portions 113 and 114 is made as small as possible so that the temperature can be switched from the internal temperature of the nucleation zone 115 to the internal temperature of the crystal growth zone 116 in a short time. In addition, temperature switching from the internal temperature of the crystal growth zone 116 to the internal temperature of the cooling zone 117 can be performed in a short time. In the first boundary portion 113 and the second boundary portion 114, the temperature can be switched in a time of about 1/100 to 1/1000 compared with the case of the conventional batch processing.

  In conventional batch processing, since it takes time to shift each process, there is a possibility that the crystal nucleus formed on the substrate changes due to migration or the like during the transition period and quality degradation proceeds. In contrast, in the present embodiment, since the temperature switching between the zones can be performed in a short time as described above, it is moved to the next zone while maintaining the crystal state formed in each zone as much as possible. be able to. As a result, it is possible to reduce the migration of crystal grains and form a substantially uniform Si crystal.

  As described above, in the continuous thin film forming method using the continuous thin film forming apparatus 100 of this embodiment, the first reaction gas used for nucleation and the second reaction gas used for crystal growth are appropriately selected. Thus, a uniform thin film can be formed on the substrate by adjusting the size of the crystal grains. Moreover, although the said Example demonstrated the case where a thin film was formed only in the single side | surface of the board | substrate 10, it is not restricted to this, By supplying the 1st reaction gas 11 and the 2nd reaction gas to both surfaces of the board | substrate 10, it is. A thin film can be formed on both sides of the substrate 10.

(Second Embodiment)
A second embodiment of the method and apparatus for forming a continuous thin film of the present invention will be described below using the example shown in FIG. In the continuous thin film forming apparatus 200 of this embodiment, in the heating furnace 220, the gap 220a is provided between the first heating unit 221 and the second heating unit 222 and between the second heating unit 222 and the third heating unit 223, respectively. 220b. By providing such gaps 220a and 220b, the first boundary 113 and the second boundary 114 of the reaction tube 110 are directly cooled by outside air. The gaps 220a and 220b may be formed by dividing the heating furnace 220 into three parts, or may be formed by cutting off a part of the heating furnace 220.

  In the continuous thin film forming apparatus 200 of the present embodiment having the gaps 220a and 220b, the temperature distribution realized in the reaction tube 110 differs particularly around the first boundary 113 and the second boundary 114. An example of the temperature distribution inside the reaction tube 110 of this embodiment will be described with reference to FIG. In FIG. 4, the temperature change of the substrate 10 is indicated by reference numeral 30, and the temperature distribution inside the reaction tube 110 is indicated by reference numeral 31.

  In the present embodiment, the boundary portions 113 and 114 are configured to be cooled with outside air, so that the temperature 31 inside the reaction tube 110 is rapidly decreased at the first boundary portion 113 and the second boundary portion 114. By such rapid cooling, the crystal grains formed on the substrate 10 are stably fixed. The time for rapid cooling with outside air at the first boundary 113 and the second boundary 114 is preferably, for example, an extremely short time of 0.1 seconds or less. In such a short time, the temperature 30 of the substrate 10 hardly decreases.

  As described above, in the present embodiment, the inside of the reaction tube 110 is rapidly cooled with the outside air at the first boundary portion 113 and the second boundary portion 114, thereby preventing the migration of crystal grains and substantially uniform on the substrate 10. It is possible to form a high-quality thin film composed of various crystal grains.

  The method for producing a glass substrate of the present invention comprises cutting a plurality of substrates having a thin film produced using the continuous thin film forming method and apparatus of the present invention described above into a predetermined length and sequentially cutting them in the width direction. Connect. Thereby, a two-dimensional film-forming glass substrate having a desired width can be produced. In addition, a semiconductor element or a module can be formed on the glass substrate thus manufactured.

  According to the present invention, by using different reaction gases for nucleation and crystal growth, various thin films having a predetermined crystal grain size can be continuously formed on a substrate at high speed, and a continuous thin film forming method and apparatus It is possible to provide a film-forming glass substrate and a semiconductor element. A thin film composed of substantially uniform crystal grains can be formed on the substrate by suitably selecting the reaction gas and controlling the gas flow rate and temperature appropriately. Furthermore, a substrate having a desired thin film can be manufactured by adjusting the length of the nucleation zone, the crystal growth zone, the cooling zone, and the like.

  Since the substrate on which the thin film is formed by the continuous thin film forming method of the present invention is formed in a thin film shape, the product using the same is reduced in weight, and is flexible enough to be easily deformed. Compared to a high glass substrate, it can be used for more applications.

It is a schematic block diagram which shows one Example of the continuous thin film formation apparatus concerning the 1st Embodiment of this invention. It is a figure which shows typically the temperature change of the inside of the reaction tube of 1st Embodiment, and a board | substrate. It is a schematic block diagram which shows one Example of the continuous thin film forming apparatus concerning the 2nd Embodiment of this invention. It is a figure which shows typically the inside of the reaction tube of 2nd Embodiment, and the temperature change of a board | substrate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Substrate 11 1st reaction gas 12 2nd reaction gas 13 Inert gas 14 Cooling gas 100, 200 Continuous thin film formation apparatus 110 Reaction tube 111 Inlet 112 Extraction port 113 1st boundary part 114 2nd boundary part 115 Nuclei Formation zone 116 Crystal growth zone 117 Cooling zone 120, 220 Heating furnace 121, 221 First heating unit 122, 222 Second heating unit 123, 223 Third heating unit 124 Temperature control unit 125-127 Susceptor 130 Gas flow rate control unit 131 First DESCRIPTION OF SYMBOLS 1 Supply part 132 2nd supply port 133 3rd supply port 134 4th supply port 135 1st exhaust port 136 2nd exhaust port 141 Supply drum 142 Winding drum 143 Movement speed control part

Claims (26)

A thin film composed of the components of the reaction gas is continuously formed on the substrate using a reaction tube that continuously passes the strip-shaped substrate and the reaction gas inside and a heating furnace that is heated from the outside of the reaction tube. A continuous thin film forming method comprising:
The reaction tube is divided into a nucleation zone, a crystal growth zone, and a cooling zone in a direction of passing the substrate;
The first reaction gas is supplied from the first supply port provided on the inlet side in the nucleation zone to the inside of the nucleation zone and is exhausted from the first exhaust port provided on the outlet side. To form a predetermined crystal nucleus,
A second exhaust gas provided on the outlet side by supplying a second reaction gas different from the first reaction gas into the inside of the crystal growth zone from a second supply port provided on the inlet side in the crystal growth zone. By evacuating from the mouth, the crystal nucleus grows to form a crystal,
A continuous thin film forming method, wherein the substrate is cooled in the cooling zone to fix the crystal to form a thin film. The continuous heating film forming method according to claim 1, wherein the heating furnace heats the nucleation zone, the crystal growth zone, and the cooling zone independently. 3. The continuous thin film forming method according to claim 1, wherein the first reaction gas contains more chlorine component than the second reaction gas. 4. The first reaction gas is a gas obtained by mixing dichlorosilane (SiH ₂ Cl ₂ ) with silicon tetrachloride (SiCl ₄ ) or chlorine (Cl ₂ ). The method for forming a continuous thin film according to Item. 5. The continuous thin film forming method according to claim 1, wherein the second reaction gas is dichlorosilane (SiH ₂ Cl ₂ ). A cooling gas is supplied to the inside of the cooling zone from a third supply port provided on the inlet side of the cooling zone, and exhausted from an outlet for drawing the substrate out of the reaction tube. The continuous thin film formation method of any one of Claims 1 thru | or 5. The continuous thin film forming method according to claim 6, wherein the cooling gas is hydrogen (H ₂ ). In the nucleation zone, a fourth supply port is provided between the introduction port for introducing the substrate and the first supply port, and a predetermined non-circulation is provided from the fourth supply port to the inside of the nucleation zone. The continuous thin film forming method according to claim 1, wherein an active gas is supplied and exhausted from the inlet. The substrate is temporarily cooled at a boundary portion between the nucleation zone and the crystal growth zone and a boundary portion between the crystal growth zone and the cooling zone. The continuous thin film formation method of any one of Claims 1-3. The said thin film has a polycrystalline structure. The continuous thin film formation method of any one of Claim 1 thru | or 9 characterized by the above-mentioned. The continuous thin film forming method according to claim 10, wherein the thin film is a polysilicon thin film. The continuous thin film forming method according to any one of claims 1 to 11, wherein thermal CVD is used as a heating means of the heating furnace. The method for forming a continuous thin film according to any one of claims 1 to 11, wherein plasma CVD is used as a heating means of the heating furnace. The continuous thin film forming method according to claim 1, wherein quartz glass having a thickness of 30 μm to 300 μm is used as the substrate. A substrate provided with the thin film is produced by cutting the substrate manufactured by the continuous thin film forming method according to any one of claims 1 to 14 into a desired length and connecting in a width direction. A method for producing a glass substrate, comprising: A reaction tube for continuously passing a strip-shaped substrate and a reaction gas through the inside, and a heating furnace for heating from the outside of the reaction tube, and continuously forming a thin film made of the components of the reaction gas on the substrate A continuous thin film forming apparatus,
The reaction tube is divided into a nucleation zone, a crystal growth zone, and a cooling zone in a direction in which the substrate passes.
A first supply port provided on the inlet side of the nucleation zone for supplying a first reaction gas into the nucleation zone;
A first exhaust port provided on the outlet side of the nucleation zone for exhausting the first reaction gas;
A second supply port which is provided on the inlet side of the crystal growth zone and supplies a second reaction gas different from the first reaction gas into the crystal growth zone;
A second exhaust port provided on the outlet side of the crystal growth zone for exhausting the second reaction gas;
A continuous thin film forming apparatus comprising: The heating furnace includes a first heating unit that heats the nucleation zone, a second heating unit that heats the crystal growth zone, and a third heating unit that heats the cooling zone. The continuous thin film forming apparatus according to claim 16, wherein heating by the three heating units is independently controlled. The reaction tube is characterized in that the cross section of the boundary between the nucleation zone and the crystal growth zone and the cross section of the boundary between the crystal growth zone and the cooling zone are narrower than the cross section of each zone. The continuous thin film forming apparatus according to claim 16 or 17. A third supply port for supplying a cooling gas to the inside of the cooling zone on the inlet side of the cooling zone, and exhausting the cooling gas from an outlet for drawing the substrate out of the reaction tube. The continuous thin film forming apparatus according to claim 16, wherein the apparatus is a continuous thin film forming apparatus. The nucleation zone is provided with a fourth supply port between the introduction port for introducing the substrate and the first supply port, and a predetermined inert gas is introduced from the fourth supply port into the nucleation zone. The continuous thin film forming apparatus according to any one of claims 16 to 19, wherein is supplied and exhausted from the inlet. 21. The susceptor is disposed inside each of the nucleation zone, the crystal growth zone, and the cooling zone in proximity to the substrate. Continuous thin film forming equipment. The heating furnace has a gap for bringing the reaction tube into contact with the outside air at each of a boundary between the nucleation zone and the crystal growth zone and a boundary between the crystal growth zone and the cooling zone. The continuous thin film forming apparatus according to any one of claims 16 to 21, wherein the apparatus is a continuous thin film forming apparatus. 23. The continuous thin film forming apparatus according to claim 16, further comprising means for supplying a belt-shaped substrate and means for winding the film-formed substrate. .   A strip-shaped film-formed glass substrate manufactured using the continuous thin film forming apparatus according to any one of claims 16 to 23. 25. A two-dimensional film-formation glass substrate produced by cutting the strip-form film-formation glass substrate of claim 24 into a desired length and connecting it in the width direction. A semiconductor element or a semiconductor module manufactured using the belt-shaped film-formed glass substrate according to claim 24 or the two-dimensional film-formed glass substrate according to claim 25.

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