Heat treatment method and heat treatment device

Abstract

The present invention provides a heat treatment method and a heat treatment apparatus. The heat treatment method of one embodiment of the present invention comprises: forming a film on a substrate with a hydrogen concentration of 5×10 19 atoms / cm 3 and forming a polycrystalline silicon film from the amorphous silicon film by irradiating the substrate with microwaves to heat the amorphous silicon film. The present invention can form a polycrystalline silicon film with large grain size.

Description

Technical Field

[0001] The present invention relates to a heat treatment method and a heat treatment device. Background Art

[0002] There is known a technique for forming a polycrystalline semiconductor film from an amorphous semiconductor film by annealing an amorphous semiconductor film formed on a substrate by irradiating the substrate with microwaves (for example, see Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2012-234864 Summary of the Invention

[0006] Technical problem to be solved by the invention

[0007] The present invention provides a technology capable of forming a polycrystalline silicon film having large grain sizes.

[0008] Technical solutions to technical problems

[0009] A heat treatment method according to one embodiment of the present invention comprises: forming a film on a substrate with a hydrogen concentration of 5×10 19 atoms / cm 3 and forming a polycrystalline silicon film from the amorphous silicon film by irradiating the substrate with microwaves to heat the amorphous silicon film.

[0010] Effects of the Invention

[0011] According to the present invention, a polycrystalline silicon film having a large grain size can be formed. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a diagram showing an example of a heat treatment apparatus.

[0013] Figure 2 This is a flowchart showing an example of the operation of the heat treatment apparatus according to one embodiment.

[0014] Figure 3 It is a diagram showing the crystallization state of the a-Si film.

[0015] Figure 4 This is a graph showing the correlation between the hydrogen concentration in an a-Si film and the activation energy of crystallization.

[0016] Figure 5 It indicates the evaluation of the hydrogen concentration in the membrane is 1×10 20 atoms / cm 3A diagram showing the crystallinity of an a-Si film subjected to microwave heating.

[0017] Figure 6 The hydrogen concentration in the membrane is 5×10 19 atoms / cm 3 A diagram showing the crystallinity of an a-Si film subjected to microwave heating.

[0018] Figure 7 The hydrogen concentration in the membrane is 3×10 19 atoms / cm 3 A diagram showing the crystallinity of an a-Si film subjected to microwave heating.

[0019] Figure 8 It indicates the evaluation of the hydrogen concentration in the membrane is 1×10 20 atoms / cm 3 A diagram showing the crystallinity of an a-Si film subjected to resistance heating.

[0020] Description of Reference Numerals

[0021] 10. Processing Container

[0022] 13 Crystal Boat

[0023] 16 Gas supply pipe

[0024] 24 resistance heating element

[0025] 27 Microwave introduction part

[0026] 90 Control Department. DETAILED DESCRIPTION

[0027] Hereinafter, non-limiting exemplary embodiments of the present invention will be described with reference to the accompanying drawings. In all the accompanying drawings, the same or corresponding components or parts are marked with the same or corresponding reference numerals, and repeated descriptions are omitted.

[0028] [Heat treatment equipment]

[0029] Reference Figure 1 , a heat treatment apparatus according to one embodiment is described. Figure 1 This is a diagram showing an example of a heat treatment apparatus. Figure 1 The heat treatment apparatus shown is a batch type apparatus that performs heat treatment on a plurality of substrates at a time.

[0030] The heat treatment apparatus includes a processing vessel 10. Processing vessel 10 has a vertically elongated cylindrical shape and houses semiconductor wafers (hereinafter referred to as "wafers W") serving as substrates. Processing vessel 10 comprises a cylindrical inner tube 10a and a topped cylindrical outer tube 10b with an open lower end that covers the outside of inner tube 10a. Inner tube 10a and outer tube 10b are made of quartz, a heat-resistant material with low microwave absorptivity, and are coaxially arranged to form a double-tube structure.

[0031] The lower end of the processing vessel 10 is supported by a cylindrical manifold 11, for example, made of stainless steel. An outer tube support portion 11a is formed at the upper end of the manifold 11. This outer tube support portion 11a supports the lower end of the outer tube 10b. A sealing member 11b, such as an O-ring, is provided between the outer tube support portion 11a and the lower end of the outer tube 10b. This sealing member 11b maintains an airtight seal within the outer tube 10b.

[0032] An annular inner tube support portion 11c is formed on the inner wall of the manifold 11. The inner tube support portion 11c supports the lower end of the inner tube 10a. A cover 12 is airtightly mounted to the opening at the lower end of the manifold 11, sandwiching a sealing member 11d such as an O-ring. This seals the lower end opening of the processing container 10, i.e., the opening of the manifold 11, airtightly. The cover 12 is formed, for example, of stainless steel. The upper surface of the cover 12 is formed, for example, into a concave shape. As a result, microwaves introduced into the metal chamber 21 from the microwave inlet portion 27 (described later) are reflected and scattered by the upper surface of the cover 12, and are evenly distributed within the metal chamber 21.

[0033] A rotation shaft 14 is provided through the center of the cover 12 via a magnetic fluid seal (not shown) to rotatably support the wafer boat 13. The rotation shaft 14 is rotatably supported by a lifting unit (not shown) such as a boat elevator.

[0034] A wafer boat 13 holding wafers W is placed at the upper end of the rotating shaft 14. The wafer boat 13 can be housed within the processing container 10, holding multiple wafers W at predetermined intervals in a rack-like manner. The wafer boat 13 and the lid 12 are moved up and down by raising and lowering the elevator. This allows the wafer boat 13 to be inserted into and removed from the processing container 10. A heat-insulating cylinder 15 is provided between the lid 12 and the wafer boat 13. The heat-insulating cylinder 15, made of, for example, quartz, prevents the wafer boat 13 from cooling due to heat transfer from the lid 12, thereby keeping the wafer boat 13 warm.

[0035] The manifold 11 is provided with a gas supply pipe 16 for supplying a film forming gas, an etching gas or other processing gas and a purge gas or other prescribed gas into the inner tube 10a. The gas supply pipe 16 is formed of, for example, quartz. The gas supply pipe 16 is supported so as to pass through the manifold 11. The front end of the gas supply pipe 16 is open, and the prescribed gas is released from the front end. The prescribed gas with a controlled flow rate is supplied to the processing container 10 through the gas supply pipe 16. In addition, Figure 1 In the example shown, one gas supply pipe 16 is shown, but the present invention is not limited thereto. For example, a plurality of gas supply pipes 16 may be provided depending on the type of gas. Figure 1 In FIG. 1 , the flow of the gas supplied from the gas supply pipe 16 is indicated by thin arrows.

[0036] The manifold 11 is provided with an exhaust pipe 17 for exhausting the gas in the processing container 10 . The gas in the processing container 10 is exhausted through the exhaust pipe 17 .

[0037] A temperature sensor 18 for detecting the temperature inside the inner tube 10a is provided in the manifold 11. The temperature sensor 18 is provided in the inner tube 10a along its longitudinal direction, and its base end is bent into an L-shape to pass through the manifold 11. The temperature sensor 18 is, for example, a thermocouple or a temperature resistor.

[0038] A metal chamber 21 is provided around the processing vessel 10. The metal chamber 21 has a curved top surface and is cylindrical with an open bottom. The lower end of the metal chamber 21 is supported by the manifold 11. The metal chamber 21 is formed of a metal material such as stainless steel, alumina, or an aluminum alloy, and its inner surface is mirror-polished to allow multiple reflections of the introduced microwaves, thereby efficiently heating the wafer W.

[0039] A heat insulator 23 is installed on the inner circumferential wall of the metal chamber 21. The heat insulator 23 is cylindrical in shape. The lower end of the heat insulator 23 is supported by the manifold 11. The heat insulator 23 is formed, for example, from a mixture of amorphous silica and alumina, which have low thermal conductivity and are relatively flexible. The heat insulator 23 is positioned so that its inner circumference is spaced a predetermined distance from the outer surface of the outer tube 10b.

[0040] A resistance heating element 24 is arranged in a spirally wound manner on the inner circumferential wall of the heat insulating component 23. The resistance heating element 24 is connected to a power source, generates heat by supplying electricity, and heats the wafer W held in the wafer boat 13. The resistance heating element 24 can be, for example, a heating wire formed by a wire rod having a circular cross-sectional shape. For example, a groove is formed in a spiral shape on the inner circumferential wall of the heat insulating component 23, and the resistance heating element 24 is embedded in the groove and fixed. In addition, the resistance heating element 24 can be divided into a plurality of regions in the up and down directions. When the resistance heating element 24 is divided into a plurality of regions in the up and down directions, the temperature of the processing container 10 in the up and down directions can be adjusted by controlling the heat generation of the resistance heating element 24 in each region.

[0041] A refrigerant (e.g., air) is introduced into the space between the outer tube 10b and the metal chamber 21 from a refrigerant inlet (not shown) formed in the manifold 11. A refrigerant exhaust 25 is provided at the top of the metal chamber 21, and the refrigerant introduced into the space can be discharged from the refrigerant exhaust 25. This allows the interior of the processing container 10 to be cooled in a short time. Figure 1 In FIG. 1 , the flow of the refrigerant introduced from the refrigerant inlet portion is indicated by thick arrows.

[0042] A water cooling jacket 26 is provided around the metal chamber 21 so as to cover the outer circumference and top of the metal chamber 21. The lower end of the water cooling jacket 26 is supported by the base plate 22. The water cooling jacket 26 has a cooling water flow path 26a inside, through which cooling water can flow. By supplying cooling water to the cooling water flow path 26a to cool the metal chamber 21, it is possible to suppress the influence of heat from the inside of the metal chamber 21 to the outside.

[0043] The heat treatment apparatus further includes a microwave introduction unit 27 for introducing microwaves into the metal chamber 21 to heat the wafers W within the processing container 10. The microwave introduction unit 27 includes a microwave source 27a and a waveguide 27b. The microwave source 27a generates microwaves. The waveguide 27b is provided to pass through the metal chamber 21, the heat insulating member 23, and the water cooling jacket 26, and transmits the microwaves generated by the microwave source 27a and introduces them into the metal chamber 21.

[0044] The frequency of the microwave is, for example, 2.45 GHz to 100 GHz, preferably 20 GHz to 100 GHz (quasi-millimeter wave to millimeter wave band), and more preferably 28 GHz. By setting the frequency of the microwave to 20 GHz to 100 GHz, it is possible to suppress the generation of standing waves in the metal chamber 21, so as to uniformly heat the multiple wafers W housed in the processing container 10. In addition, by setting the frequency of the microwave to 20 GHz to 100 GHz, it is possible to introduce the microwave into the metal chamber 21 with high output. Generally speaking, when using microwaves with a frequency of 30 GHz or more with an output of more than 10 kW, a gyrotron can be used, but the gyrotrons sold on the market are large. Therefore, by setting the frequency of the microwave to 28 GHz, a relatively small gyrotron can be used when generating microwaves with a high output of about 10 kW. Therefore, it is easy to apply to heat treatment devices. In addition, when the frequency of the microwave is 28 GHz, arc discharge does not occur under reduced pressure, so reduced pressure treatment can be implemented in a state where microwaves are introduced into the processing container 10. Examples of the reduced pressure treatment include low-pressure CVD (LPCVD: Low Pressure Chemical Vapor Deposition) and atomic layer deposition (ALD: Atomic Layer Deposition).

[0045] The heat treatment apparatus further includes a control unit 90 for controlling the actions of the various components of the heat treatment apparatus. The control unit 90 may be, for example, a computer. The computer program for controlling the actions of the entire heat treatment apparatus is stored in a storage medium. The storage medium may be a floppy disk, an optical disk, a hard disk, a flash memory, a DVD, or the like.

[0046] [Operation of the heat treatment device]

[0047] The operation of the heat treatment apparatus (heat treatment method) according to one embodiment will be described. Figure 2 This is a flowchart showing an example of the operation of the heat treatment apparatus according to one embodiment. Figure 2 The heat treatment method shown is a method of forming a polysilicon film (hereinafter also referred to as a "p-Si film") on a wafer W using the above-mentioned heat treatment apparatus.

[0048] First, in Figure 2 After the heat treatment method is started, the control unit 90 controls the various parts of the heat treatment apparatus to introduce a wafer W having an amorphous silicon film (hereinafter referred to as "a-Si film") formed on the surface thereof (step S21). For example, the a-Si film having a high hydrogen concentration has a hydrogen concentration of 5×10 19 atoms / cm 3 Above, 2×10 21 atoms / cm 3In one embodiment, the control unit 90 controls the lifting unit to carry the wafer boat 13 holding a plurality of wafers W into the processing container 10, and the lower opening of the processing container 10 is sealed airtightly with the lid 12. On each wafer W, a film with a hydrogen concentration of 5×10 19 atoms / cm 3 The above a-Si film is formed. Furthermore, the control unit 90 exhausts the gas in the processing container 10 via the exhaust pipe 17, reducing the pressure in the processing container 10 to a predetermined value. The hydrogen concentration in the film is a value measured by Rutherford Back-Scattering Spectroscopy (RBS) or Fourier Transform Infrared Spectroscopy (FTIR).

[0049] Next, the control unit 90 controls the various parts of the heat treatment apparatus to heat the plurality of wafers W housed in the processing container 10 with microwaves (step S22). In one embodiment, the control unit 90 controls the microwave generating source 27a to introduce microwaves into the metal chamber 21 via the waveguide 27b to heat the wafer W to a predetermined temperature. By heating the wafer W with microwaves, the a-Si film can be crystallized at a low temperature and in a short time to form a p-Si film with a large particle size, compared to the case where the wafer W is heated by heating a resistance heating element. Hereinafter, the heating of the wafer W with microwaves will be referred to as microwave heating, and the heating of the wafer W with a resistance heating element will be referred to as resistance heating. In addition, the predetermined temperature is the temperature at which the a-Si film crystallizes, for example, 550°C to 650°C.

[0050] Alternatively, the control unit 90 may control the power supply to generate heat from the resistance heating element 24, while simultaneously controlling the microwave generator 27a to introduce microwaves into the metal chamber 21 to heat the wafer W to a predetermined temperature. In other words, the wafer W may be heated to a predetermined temperature through both resistance heating and microwave heating. The predetermined temperature is the temperature at which the a-Si film crystallizes, for example, 550°C to 650°C.

[0051] Alternatively, the control unit 90 may control the power supply to generate heat from the resistance heating element 24 to heat the wafer W to a first temperature, and then control the microwave generator 27a to introduce microwaves into the metal chamber 21 to heat the wafer W to a second temperature. In other words, after preheating by resistance heating, the main heating may be performed by microwave heating. The first temperature is lower than the a-Si film crystallization temperature, for example, 200°C to 400°C. The second temperature is higher than the first temperature, at which the a-Si film crystallizes, for example, 550°C to 650°C.

[0052] As described above, by combining resistance heating and microwave heating, it is possible to suppress heat release from the wafer W to the metal chamber 21 via the quartz tube (inner tube 10a and outer tube 10b), which is difficult to heat with microwaves. Therefore, the wafer W can be heated quickly with good in-plane uniformity and good inter-plane uniformity. As a result, a polycrystalline silicon film can be formed with good in-plane uniformity and good inter-plane uniformity.

[0053] Next, the control unit 90 controls various components of the thermal treatment apparatus to transport the heat-treated wafers W out of the processing chamber 10 (step S23). In one embodiment, the control unit 90 supplies a purge gas from the gas supply pipe 1 into the processing chamber 10 to return the pressure inside the processing chamber 10 to atmospheric pressure. Furthermore, the control unit 90 controls the elevator to transport the wafer boat 13 out of the processing chamber 10, completing the process.

[0054] Next, the process of forming a film on a wafer W with a hydrogen concentration of 5×10 19 atoms / cm 3 The above is an example of a method for forming an a-Si film. The a-Si film can be formed using, for example, the above-mentioned heat treatment apparatus or other film forming apparatus.

[0055] The wafer W is placed in a processing container capable of reducing pressure, the pressure in the processing container is adjusted to a predetermined pressure, and the wafer W is heated to a predetermined temperature. Then, a silicon-containing gas is supplied to the wafer W. Thus, a film with a hydrogen concentration of 5×10 19 atoms / cm 3 The specified pressure and the specified temperature are determined by the type of silicon-containing gas. For example, when silane (SiH4) gas is used as the silicon-containing gas, the pressure in the processing container is adjusted to 100Pa to 600Pa, and the wafer W is heated to 400℃ to 470℃, thereby forming a film with a hydrogen concentration of 5×10 19 atoms / cm 3 Furthermore, for example, when disilane (Si2H6) gas is used as the silicon-containing gas, the pressure in the processing container is adjusted to 50Pa to 500Pa, and the wafer W is heated to 300℃ to 420℃, thereby forming a film with a hydrogen concentration of 5×10 19 atoms / cm 3 The above a-Si film.

[0056] [Example]

[0057] An example conducted to confirm the effects achieved by the heat treatment apparatus according to one embodiment will be described.

[0058] In Example 1, a silicon oxide (SiO2) film having a hydrogen concentration of 6×10 20, 5×10 19 , 3×10 19 , 1×10 19 atoms / cm 3 The silicon wafers with the a-Si film were heated at 520° C. for 50 minutes. Next, the cross section of each silicon wafer was observed with a transmission electron microscope (TEM) to confirm the crystallization state of the a-Si film.

[0059] Figure 3 This is a diagram showing the crystallization state of a-Si film. Figure 3 In the figure, starting from the left, the hydrogen concentration in the film [atoms / cm 3 ], annealing temperature [°C], annealing time [min], and TEM image. The hydrogen concentration in the film is the hydrogen concentration in the a-Si film before heating (annealing). The annealing temperature is the temperature at which the silicon wafer is heated by microwave heating. The annealing time is the time the silicon wafer is heated by microwave heating. The TEM image is an image of a cross-section of the silicon wafer after microwave heating, as observed using a TEM.

[0060] like Figure 3 As shown, it can be seen that the hydrogen concentration in the film is 6×10 20 atoms / cm 3 In the case of , the a-Si film is not crystallized. In addition, it is known that the hydrogen concentration in the film is 5×10 19 atoms / cm 3 In the case of , the a-Si film is partially crystallized. In addition, it is known that the hydrogen concentration in the film is 3×10 19 atoms / cm 3 and 1×10 19 atoms / cm 3 From the above results, it can be seen that when heating at the same temperature, the higher the hydrogen concentration in the a-Si film, the more difficult it is for crystallization to proceed.

[0061] In Example 2, the relationship between the hydrogen concentration in the film and the activation energy of crystallization was evaluated using the RBS method for a-Si films having different hydrogen concentrations in the film.

[0062] Figure 4 This is a graph showing the correlation between the hydrogen concentration in the a-Si film and the activation energy of crystallization. Figure 4 The horizontal axis represents the hydrogen concentration in the a-Si film [atoms / cm 3 ], and the vertical axis represents the activation energy of crystallization [eV].

[0063] like Figure 4As shown in FIG. 1 , it is known that the higher the hydrogen concentration in the film, the greater the activation energy of crystallization. This result shows that when an a-Si film with a high hydrogen concentration in the film is used, the temperature for crystallizing the a-Si film becomes higher.

[0064] In Example 3, the crystal grain size of the p-Si film formed by heating the a-Si film was evaluated while changing the hydrogen concentration in the a-Si film or the heating method of the a-Si film.

[0065] Figure 5 It indicates the evaluation of the hydrogen concentration in the membrane is 1×10 20 atoms / cm 3 A diagram showing the results of crystallinity of an a-Si film subjected to microwave heating. Figure 6 It indicates that the water concentration in the membrane is 5×10 19 atoms / cm 3 A diagram showing the results of crystallinity of an a-Si film subjected to microwave heating. Figure 7 It indicates that the hydrogen concentration in the membrane is 3×10 19 atoms / cm 3 A diagram showing the results of crystallinity of an a-Si film subjected to microwave heating. Figure 8 It indicates the evaluation of the hydrogen concentration in the membrane is 1×10 20 atoms / cm 3 A diagram showing the crystallinity results of an a-Si film subjected to resistance heating.

[0066] exist Figures 5 to 8 , the heating method, hydrogen concentration in the film, EBSD mapping image, average particle size, and maximum particle size are shown in order from the top.

[0067] The heating method is a method of heating the a-Si film, which can be microwave heating or resistance heating. In microwave heating, microwaves with a frequency of 28 GHz are irradiated onto the a-Si film, thereby heating the substrate with the a-Si film to a temperature of 600-650°C and maintaining it for 2-4 hours. In resistance heating, a resistance heating element is heated, thereby heating the substrate with the a-Si film to a temperature of 620-670°C and maintaining it for 6-12 hours.

[0068] The hydrogen concentration in the film is the hydrogen concentration in the a-Si film before heating.

[0069] The EBSD mapping images show the results of observing the crystal grain size of a p-Si film using the electron backscattered diffraction (EBSD) method. The image on the left shows the results when the twin boundary Σ3-CSL is used as the grain boundary, while the image on the right shows the results when the twin boundary Σ3-CSL is not used as the grain boundary.

[0070] The average grain size and the maximum grain size are respectively the average value and the maximum value of the crystal grain size of the p-Si film calculated based on an image obtained by the EBSD method.

[0071] like Figure 5 As shown, the hydrogen concentration in the film is 1×10 20 atoms / cm 3 The average and maximum grain sizes of the p-Si film after microwave heating of the a-Si film were 0.36 μm and 2.02 μm, respectively, when the twin boundary Σ3-CSL was used as the crystal grain boundary. Furthermore, when the twin boundary Σ3-CSL was not used as the crystal grain boundary, the average and maximum grain sizes were 0.48 μm and 3.71 μm, respectively.

[0072] like Figure 6 As shown, for a hydrogen concentration of 5×10 19 atoms / cm 3 The average and maximum grain sizes of the p-Si film produced by microwave heating of an a-Si film were 0.30 μm and 1.15 μm, respectively, when the twin boundary Σ3-CSL was used as the crystal grain boundary. Furthermore, when the twin boundary Σ3-CSL was not used as the crystal grain boundary, the average and maximum grain sizes were 0.43 μm and 1.35 μm, respectively.

[0073] In addition, if Figure 7 As shown, for the hydrogen concentration in the film of 3×10 19 atoms / cm 3 The average and maximum grain sizes of the p-Si film after microwave heating of the a-Si film were 0.25 μm and 0.78 μm, respectively, when the twin boundary Σ3-CSL was used as the crystal grain boundary. Furthermore, when the twin boundary Σ3-CSL was not used as the crystal grain boundary, the average and maximum grain sizes were 0.30 μm and 0.78 μm, respectively.

[0074] In addition, if Figure 8 As shown, for a hydrogen concentration of 1×10 20 atoms / cm 3The average and maximum grain sizes of the p-Si film produced by resistance heating of an a-Si film were 0.24 μm and 1.35 μm, respectively, when the twin boundary Σ3-CSL was used as the crystal grain boundary. Furthermore, when the twin boundary Σ3-CSL was not used as the crystal grain boundary, the average and maximum grain sizes were 0.44 μm and 2.15 μm, respectively.

[0075] according to Figures 5 to 7 As a result, it can be said that by using a membrane with a hydrogen concentration of 1×10 20 atoms / cm 3 and 5×10 19 atoms / cm 3 a-Si film, with a hydrogen concentration of 3×10 19 atoms / cm 3 Compared with the case of the a-Si film, a p-Si film with a larger grain size can be formed.

[0076] In addition, according to Figure 5 and Figure 8 As a result, it can be said that when the hydrogen concentration in the film is the same, by using microwave heating, regardless of whether it is low-temperature and short-time heating, a p-Si film with a larger grain size can be formed compared with the case of using resistance heating.

[0077] As described above, according to one embodiment, microwaves are irradiated onto a substrate to heat an a-Si film formed on the substrate, causing the a-Si film to crystallize and form p-Si. This allows for the formation of a p-Si film with a large particle size at a low temperature and in a short time, compared to resistance heating using a resistance heating element. In other words, a p-Si film with high carrier mobility can be formed at a low temperature and in a short time.

[0078] In addition, according to one embodiment, the hydrogen concentration in the membrane is 5×10 19 atoms / cm 3 The above a-Si film is used to form a p-Si film. 19 atoms / cm 3 Compared with the case where a p-Si film is formed from a thin a-Si film, a p-Si film with a larger grain size can be formed. In other words, a p-Si film with high carrier mobility can be formed.

[0079] Furthermore, according to one embodiment, an a-Si film is formed on a substrate and then heated to form a p-Si film. This allows for the formation of a film with better step coverage than when the p-Si film is formed directly on the substrate.

[0080] As described above, the p-Si film formed according to one embodiment has good coverage of unevenness and high carrier mobility, and is therefore suitable as channel silicon for 3D-NAND.

[0081] In the above embodiment, the heat insulating member 23 and the resistance heating element 24 are examples of a first heating unit, and the microwave introduction unit 27 is an example of a second heating unit. Furthermore, the wafer boat 13 is an example of a substrate holder, and the gas supply pipe 16 is an example of a gas supply unit.

[0082] The embodiments disclosed herein are illustrative in all respects and should not be considered restrictive. The above embodiments may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the appended claims.

Claims

1. A heat treatment method, characterized in that: include: The hydrogen concentration in the film formed on the substrate is 5×10 19 atoms / cm 3 The above steps of amorphous silicon film; The step of heating the substrate housed in a quartz processing container with the interior thereof depressurized below atmospheric pressure at a first temperature lower than the temperature at which the amorphous silicon film crystallizes, using heat generated by a resistance heating element; and A step of forming a polycrystalline silicon film from the amorphous silicon film by heating the amorphous silicon film at a second temperature by irradiating microwaves onto the substrate housed in the processing container in a state where the interior of the processing container is depressurized below atmospheric pressure and heated by heat generated by a resistive heating element, wherein the second temperature is a temperature at which the amorphous silicon film crystallizes, which is higher than the first temperature.

2. The heat treatment method according to claim 1, wherein: The frequency of the microwave is 20 GHz to 100 GHz.

3. The heat treatment method according to claim 1 or 2, wherein: The hydrogen concentration in the film is 1×10 20 atoms / cm 3 above.

4. A heat treatment device, characterized in that include: A quartz processing container capable of reducing pressure; a gas supply unit for supplying gas to the interior of the processing container; a first heating portion provided around the processing container, which utilizes heat generated by a resistance heating element to heat the substrate housed in the processing container with the interior thereof being decompressed below atmospheric pressure at a first temperature lower than a temperature at which the amorphous silicon film is crystallized; and The second heating part heats the amorphous silicon film at a second temperature and forms a polycrystalline silicon film from the amorphous silicon film by irradiating microwaves from the outside of the processing container to the substrate housed in the processing container in a state where the interior of the processing container is depressurized below atmospheric pressure and heated by heat generated by a resistance heating element. The second temperature is a temperature at which the amorphous silicon film crystallizes, which is higher than the first temperature.

5. The heat treatment device according to claim 4, characterized in that: The processing container accommodates a plurality of substrates held in a shelf-like manner on substrate holders.

6. The heat treatment device according to claim 5, characterized in that: The frequency of the microwave is 20 GHz to 100 GHz.

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