Vapor phase growth apparatus and method for manufacturing epitaxial wafer

Abstract

Provided is a vapor-phase growth apparatus that can sufficiently ensure a movement space of a substrate carrying member when a substrate is loaded onto or unloaded from a susceptor, even if a structure in which the space between the susceptor and the lower surface of the top plate of the reaction vessel is made narrow is adopted. A susceptor lifting mechanism that lifts the susceptor between a first position and a second position is provided in the reaction chamber. In a state in which the susceptor is positioned at the first position, the upper surface of the susceptor is positioned higher than the lower surface of the preheating ring, and a raw material gas flow-through space having a predetermined height-direction dimension is ensured between the lower surface of the top plate of the reaction vessel main body. In a state in which the susceptor is positioned at the second position, the upper surface of the susceptor is positioned lower than the lower surface of the preheating ring, and a substrate loading / unloading space having a larger height-direction dimension than the raw material gas flow-through space is ensured between the upper surface of the susceptor and the lower surface of the preheating ring.

Description

Technical Field

[0001] This invention relates to a vapor phase growth apparatus for growing semiconductor single-crystal thin films on the main surface of a single-crystal substrate and a method for manufacturing epitaxial wafers using the vapor phase growth apparatus. Background Technology

[0002] Epitaxial wafers with semiconductor single-crystal thin films formed on single-crystal substrates, such as silicon epitaxial wafers with silicon single-crystal thin films (hereinafter referred to as "thin films") formed on the surface of a silicon single-crystal substrate (hereinafter referred to as "substrate") by vapor phase growth, are widely used in electronic devices such as bipolar ICs and MOS-ICs. In recent years, in the manufacture of epitaxial wafers with diameters of 200 mm and above, monolithic vapor phase growth apparatuses are becoming mainstream instead of batch processing multiple wafers. In this monolithic vapor phase growth apparatus, a substrate is horizontally rotated and held within a reaction vessel, and a raw material gas is supplied approximately horizontally and in one direction from one end of the reaction vessel to the other while the thin film is grown in the vapor phase. Furthermore, it is known that the thickness distribution of the semiconductor single-crystal layer formed on the substrate in a monolithic vapor phase growth apparatus is greatly affected by the temperature distribution within the main surface of the substrate; in particular, the outer periphery of the substrate, where temperature drops are prone to occur, tends to fluctuate towards the side with a thicker semiconductor single-crystal layer. To prevent this, in monolithic vapor deposition apparatuses, a preheating ring is typically placed around the susceptor to ensure uniform heating of the substrate's outer periphery.

[0003] In general, during the manufacturing of silicon epitaxial wafers, the substrate is heated using any method such as infrared radiation heating, high-frequency induction heating, or resistance heating. Although the silicon substrate and base are heated, the temperature of the reaction vessel is kept low, thus forming a so-called cold wall environment.

[0004] In monolithic vapor deposition apparatuses, a typical configuration involves supplying a raw material gas via a gas inlet formed at one end of a reaction vessel through a gas supply pipe. After flowing along the main surface of the substrate, the raw material gas is discharged from an outlet at the other end of the vessel. It is known that when manufacturing epitaxial wafers using an apparatus with this configuration, increasing the flow rate of the raw material gas along the main surface of the substrate can effectively increase the growth rate of the silicon single-crystal thin film. For example, in Non-Patent Document 1, during the manufacturing of silicon epitaxial wafers, an increase in the relative velocity between the main surface of the substrate and the raw material gas due to an increase in the pedestal rotation speed reveals a pattern that increases the growth rate of the silicon single-crystal layer stacked on the substrate.

[0005] In the experiment disclosed in Non-Patent Document 1, the concentration and flow rate of the raw material gas supplied to the reaction vessel were set to be constant. Under these conditions, when the rotation speed of the substrate was increased, the growth rate of the silicon single crystal layer increased. Furthermore, in Non-Patent Document 2, under the aforementioned cold-wall environment, when the gas phase temperature during silicon single crystal layer growth was increased, the growth rate of the single crystal layer thermodynamically decreased in the region where the delivery rate of the raw material gas components was limited (i.e., the diffusion layer on the main surface of the substrate).

[0006] That is, if the gas flow rate on the main surface of the substrate increases, the thermal movement from the main surface of the substrate is promoted, the temperature of the main surface of the substrate decreases, and the diffusion layer thickness on the main surface of the substrate decreases due to the increased gas flow rate, while the concentration ratio of the raw material gas components in the diffusion layer increases. It is believed that these are the main reasons why the efficiency of the chemical reaction for generating silicon single crystals from the raw material gas is improved, and the growth rate of the silicon single crystal layer increases.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent No. 6068255

[0010] Patent Document 2: Japanese Patent Application Publication No. 2011-165948

[0011] Non-patent literature

[0012] Non-patent literature 1: Numerical Calculation of Silicon Epitaxial Growth Rate: Proceedings of the 75th Autumn Academic Conference of the Chinese Society of Applied Physics (Hokkaido University, Autumn 2014) 19a-A19-1

[0013] Non-Patent Literature 2: Simulation of Si Epitaxial Thin Film Fabrication Process: Journal of the Vacuum Society of Japan, Vol. 49 (2006), pp. 525-529 Summary of the Invention

[0014] Based on the above investigation, in a monolithic vapor deposition apparatus, to increase the flow rate of the raw material gas on the main surface of the substrate and improve the growth rate of the semiconductor single crystal layer, it is considered effective to adopt a structure that reduces the spatial height between the main surface of the substrate, which will serve as the raw material gas flow channel, and the lower surface of the top plate of the reaction vessel. Specifically, in the semiconductor single crystal growth process, by adopting a structure that brings the position of the substrate base closer in the height direction to the lower surface of the top plate of the reaction vessel, the aforementioned spatial height can be reduced.

[0015] Here, in a monolithic vapor deposition apparatus, the process of assembling the substrate on the base is carried out between the space between the base, the preheating ring, and the lower surface of the top plate of the reaction vessel (which becomes the raw material gas flow space during semiconductor single crystal layer growth) and the preparation chamber formed outside the main body of the reaction vessel, by moving a substrate transport member in and out. However, when the distance between the base and the lower surface of the top plate of the reaction vessel is reduced, there is a problem that it is difficult to ensure the space for the substrate transport member to move in and out.

[0016] The objective of this invention is to provide a vapor phase growth apparatus that, even with a structure that minimizes the space between the base and the preheating ring and the lower surface of the top plate of the reaction vessel, can adequately ensure the moving space of the substrate transport member when loading and unloading a substrate onto the base, and a method for manufacturing an epitaxial wafer using the apparatus.

[0017] The means used to solve the problem

[0018] The vapor phase growth apparatus of the present invention enables the vapor phase growth of a semiconductor single crystal thin film on the main surface of a single crystal substrate. It has a reaction vessel body with a gas inlet formed at a first end side in the horizontal direction and a gas outlet formed at a second end side. The single crystal substrate is held horizontally on a disk-shaped base driven to rotate in the internal space of the reaction vessel body and the single crystal substrate rotates. The raw material gas for forming the semiconductor single crystal thin film is introduced into the reaction vessel body from the gas inlet, flows along the main surface of the single crystal substrate, and is discharged from the gas outlet. A preheating ring is arranged to surround the base. Furthermore, to solve the aforementioned problems, the system also includes: a base lifting mechanism that raises and lowers the base between a first position and a second position, wherein the first position is formed such that the upper surface of the base is located above the lower surface of the preheating ring, and a raw material gas flow space with a predetermined height dimension is formed between the upper surface of the base and the lower surface of the top plate of the reaction vessel body; the second position is formed such that the upper surface of the base is located below the lower surface of the preheating ring, and a substrate loading and unloading space with a height dimension larger than the raw material gas flow space is formed between the upper surface of the base and the lower surface of the preheating ring; a substrate conveying member having a substrate holding part at its front end for loading and unloading single crystal substrates in a horizontal manner; and a substrate conveying member driving part that reciprocates the substrate conveying member in a horizontal direction between the substrate loading and unloading position and the preparation position relative to the base in the second position, wherein the substrate loading and unloading position is a position where the substrate holding part is located directly above the base, and the preparation position is a position where the substrate holding part is located in a preparation chamber formed outside the reaction vessel body.

[0019] Furthermore, the method for manufacturing an epitaxial wafer according to the present invention is characterized by using the vapor phase growth apparatus of the present invention described above, and within a reaction vessel, with the substrate in a second position, placing a single crystal substrate on the substrate, then raising the substrate with the single crystal substrate to a first position, allowing the raw material gas to circulate within the reaction vessel, and allowing a semiconductor single crystal thin film to be grown epitaxially on the single crystal substrate, thereby obtaining an epitaxial wafer.

[0020] In the vapor phase growth apparatus of the present invention, it is preferable that the first position is defined as having a height dimension of 5 mm to 15 mm for the raw material gas flow space. Furthermore, it is preferable that this first position is defined as having the main surface of the single-crystal substrate on the base aligned with the upper surface of the preheating ring.

[0021] In the vapor phase growth apparatus of the present invention, the flow direction of the raw material gas can be determined such that the side of the reaction vessel body with the preparation chamber is the first end, and the side opposite to the side with the preparation chamber relative to the rotation axis of the base is the second end. In this case, the portion of the internal space of the reaction vessel body located between the preparation chamber gate and the preheating ring becomes a gas passage, and the preparation chamber gate can be opened and closed to separate the preparation chambers. In this case, a partition plate is horizontally arranged in the gas passage, and the height position of the partition plate is determined such that the front end of the plate faces the side of the preheating ring. The space above the partition plate of the gas passage becomes an upper passage space 36A that communicates with the raw material gas flow space, and the space below the partition plate of the gas passage becomes a lower passage space that communicates with the instrumentation space below the preheating ring. It is preferable to determine the position such that the upper surface of the partition plate is also aligned with the upper surface of the preheating ring.

[0022] The base is driven to rotate, for example, via a rotating shaft member whose upper end is attached to the lower surface of the base. In this case, the base lifting mechanism causes the base and the rotating shaft member to rise and fall together.

[0023] Furthermore, in the vapor phase growth apparatus of the present invention, a plurality of lifting pins can be provided in the circumferential direction of the base such that the lower end protrudes downward from the base. These lifting pins lift the single crystal substrate by pushing up the outer periphery of the lower surface of the single crystal substrate on the base from the lower side. In this case, within the reaction vessel body, a substrate lifting section having lifting pin drive arms and lifting sleeves is provided below the preheating ring. A plurality of lifting pin drive arms are provided corresponding to a plurality of lifting pins, and a lifting pin force-applying section is formed at the front end for applying force to each corresponding lifting pin from below. The lifting sleeve allows rotational drive of the rotating shaft member and is coaxially arranged on the outside of the rotating shaft member, capable of moving up and down along the axis of the rotating shaft member, and is engaged with the base end of the lifting pin drive arm.

[0024] Invention Effects

[0025] The vapor phase growth apparatus of the present invention is configured such that by using a base lifting mechanism to raise and lower the base, the height direction of the base within the reaction vessel body can be changed and maintained. By changing the position of the base, the height dimension of the raw material gas flow space formed between the main surface of the single crystal substrate mounted on the base and the lower surface of the upper wall of the reaction vessel body can be changed stepwise or steplessly. This makes it possible to adjust the flow rate of the raw material gas during the growth of the semiconductor single crystal layer on the single crystal substrate, and even the semiconductor single crystal layer itself.

[0026] Furthermore, in this invention, a base lifting mechanism is provided that allows the base to move up and down between a first position and a second position. A substrate transport member is used to load and unload single-crystal substrates relative to the base in the second position. In the first position, the upper surface of the base is positioned above the lower surface of the preheating ring, and a raw material gas flow space with a predetermined height dimension is formed between the base and the lower surface of the top plate of the reaction vessel body. In the second position, the upper surface of the base is positioned below the lower surface of the preheating ring, and a substrate loading and unloading space with a height dimension larger than the raw material gas flow space is formed between the upper surface of the base and the lower surface of the preheating ring. Therefore, even with a structure that minimizes the space between the base and the preheating ring and the lower surface of the top plate of the reaction vessel, sufficient movement space for the substrate transport member is ensured below the preheating ring when loading and unloading substrates onto the base. Attached Figure Description

[0027] Figure 1 This is a schematic diagram illustrating an example of the overall structure of the vapor phase growth apparatus of the present invention.

[0028] Figure 2 This is a side sectional view of the reaction chamber.

[0029] Figure 3 This is a schematic diagram of a silicon epitaxial wafer.

[0030] Figure 4 It is shown Figure 1 A perspective view of an example of the lifting section of the base in a vapor phase growth apparatus.

[0031] Figure 5 It is Figure 4 A three-dimensional view of the lifting part of the central lifting pin that can be viewed from a perspective.

[0032] Figure 6 yes Figure 1 A block diagram of the control system for the vapor phase growth apparatus.

[0033] Figure 7 It is shown Figure 6 A flowchart illustrating the processing flow of a control program in a control system.

[0034] Figure 8 This is an explanation Figure 1 The first image shows the operation of the vapor phase growth apparatus.

[0035] Figure 9 This is an explanation Figure 1 The second image shows the operation of the vapor phase growth apparatus.

[0036] Figure 10 This is an explanation Figure 1 The third image shows the operation of the vapor phase growth apparatus.

[0037] Figure 11 This is an explanation Figure 1 The fourth image shows the operation of the vapor phase growth apparatus.

[0038] Figure 12 This is an explanation Figure 1 The fifth image shows the operation of the vapor phase growth apparatus.

[0039] Figure 13 This is an explanation Figure 1 The sixth image shows the operation of the vapor phase growth apparatus. Detailed Implementation

[0040] The following description, based on the accompanying drawings, illustrates the methods for implementing the present invention.

[0041] Figure 1 This is a side cross-sectional view schematically illustrating an example of the vapor phase growth apparatus of the present invention. As shown in Figure 3, the vapor phase growth apparatus 100 is used to fabricate a silicon epitaxial wafer EW by vapor phase growth of a silicon single crystal thin film EL on the main surface (upper surface) of a silicon single crystal substrate W (hereinafter referred to as "substrate W"). Figure 1 As shown, the vapor phase growth apparatus 100 includes a reaction chamber 1 for vapor-phase growth of a silicon single crystal thin film EL on a substrate W, a preparation chamber (the internal space forms a preparation chamber) 103 for transporting the substrate W into the interior of the reaction chamber 1, and a loading and locking chamber 104 connected to the preparation chamber 103. The preparation chamber 103 is disposed between the reaction vessel body 2 and the loading and locking chamber 104.

[0042] Inside the preparation chamber 103, a transport robot 107 is provided for transferring substrate W between the loading and locking chamber 104 and the reaction chamber 1. The transport robot 107 has multiple robotic arms 105a, 105b, and 105c forming a linkage mechanism. The robotic arms 105a, 105b, and 105c are interconnected in a manner capable of rotating about their respective rotation axes A1, A2, and A3. Driven by a drive arm 107m, the robotic arm 105c rotates, and the robotic arm 105a (hereinafter referred to as "substrate transport member 105a"), which forms the end of the substrate transport member, is driven to move forward and backward in the horizontal direction. A substrate holding portion 105H is provided at the front end of the substrate transport member 105a. A substrate is placed on the upper surface of the substrate holding portion 105H, and by moving the substrate transport member 105a forward and backward in this state, the substrate can be transported. That is, the transport robot 107 functions as a drive unit for the substrate transport member, relative to the second position described later (…). Figure 2 The substrate holding part 105H is located in the substrate loading and unloading position directly above the substrate holding part 105H and the preparation position located in the preparation chamber formed outside the reaction vessel body 2. The substrate conveying member 105a is moved back and forth in the horizontal direction.

[0043] In the portion of the preparation chamber 103 connected to the reaction vessel body 2, a preparation chamber gate 108 (L-type gate valve) is provided for ensuring an airtight connection between the reaction vessel body 2 and the preparation chamber 103. Additionally, a loading and locking chamber 104 is used to store multiple substrates W in a stacked configuration.

[0044] Figure 2 The detailed structure of reaction chamber 1 is shown. Reaction chamber 1 has a reaction vessel body 2 with a gas inlet 22 formed at a first end in the horizontal direction and a gas outlet 21 formed at a second end. The feed gas G for thin film formation is configured such that it is introduced into the reaction vessel body 2 through the gas inlet 22, flows along the main surface of the substrate W, which is held approximately horizontally and rotated, within the internal space 5 of the reaction vessel body 2, and is then discharged from the gas outlet 21. The reaction vessel body 2 as a whole, as well as other internal structural components, are constructed of metallic materials such as quartz and stainless steel.

[0045] exist Figure 2 In the internal space 5 of the reaction vessel body 2, a disk-shaped base 9 is disposed, which is driven by a motor 40 to rotate about a vertical axis of rotation O. A shallow countersunk hole 9B is formed on its upper surface (see reference). Figure 4 Within the center, only one piece is configured for manufacturing. Figure 3 The substrate W of the silicon epitaxial wafer EW. That is, the reaction chamber 1 is configured as a horizontal monolithic vapor phase growth apparatus. The substrate W has a diameter of, for example, 100 mm or more. Additionally, as... Figure 1As shown, infrared heating lamps 11 for heating the substrate are arranged at predetermined intervals above and below the reaction vessel body 2, corresponding to the arrangement area of ​​the substrate W. Additionally, as... Figure 2 As shown, a preheating ring 32 is arranged inside the reaction vessel body 2 in a manner that surrounds the base 9.

[0046] The raw material gas G is used for the vapor-phase growth of a silicon single-crystal thin film on the aforementioned substrate W, and is selected from silicon compounds such as SiHCl3, SiCl4, SiH2Cl2, SiH4, and Si2H6. The raw material gas G may appropriately incorporate B2H6 or PH3 as a doping gas, and H2, N2, Ar, etc., as dilution gases. Furthermore, before the vapor-phase growth of the thin film, during substrate pretreatment (e.g., removal of natural oxide film, removal of attached organic matter), a pretreatment gas diluted with a dilution gas (appropriately selected from HCl, HF, ClF3, NF3, etc.) is supplied to the reaction vessel body 2, or high-temperature heat treatment is performed in an H2 ambient gas environment.

[0047] like Figure 2 As shown, the base 9 is rotated by a motor 40 via a rotating shaft member 15 whose upper end is attached to the lower surface of the base 9. The front end of the rotating shaft member 15 is attached to the central region of the lower surface of the base 9. Furthermore, at the midpoint of the axial direction of the rotating shaft member 15, the base ends of a plurality of base support arms 15D are attached. The front end of each base support arm 15D extends horizontally along the radial direction of the base 9, and each front end is attached to the lower surface of the base 9 by a connecting pin 15C. The connecting pin 15C serves as a spacer to form a small gap (approximately 1 mm in this embodiment) between the base support arm 15D and the lower surface of the base 9. Figure 5 As shown, the rotating shaft component 15 consists of a shaft body 15A and a thermocouple 15B. The outer circumferential surface of the upper end of the shaft body 15A becomes a tapered surface with a smaller diameter at the front end. The upper end of the shaft body 15A with its reduced diameter is fitted into a cylindrical sleeve 15S in a manner that prevents relative rotation (Furthermore, in... Figure 5 (The diagram of the base support arm 15D and the connecting pin 15C is omitted.)

[0048] In reaction chamber 1, a mechanism is provided to allow base 9 to... Figure 2 The first position PP and the second position PS shown (in) Figure 2In the text, PP, PS, and Ph represent the positions of the substrate BP1, but in the following description, they are used to indicate the position of the base 9. The base lifting mechanism 39 moves between these positions. When the base 9 is in the first position PP, the upper surface of the base 9 is positioned above the lower surface of the preheating ring 32, and a raw material gas flow space 5P with a predetermined height dimension is ensured between the upper surface of the base 9 and the lower surface of the top plate of the reaction vessel body 2 (see reference). Figure 13 The first position PP mentioned above is determined by a relatively small value in the height direction of the ensured raw material gas flow space 5P, which is between 5 mm and 15 mm (approximately 10 mm in this embodiment).

[0049] On the other hand, with the base 9 in the second position PS, the upper surface of the base 9 is located below the lower surface of the preheating ring 32, and a substrate loading / unloading space 5T (refer to) is ensured between the upper surface of the base 9 and the lower surface of the preheating ring 32, with the height dimension being larger than the raw material gas flow space 5P. Figures 9-12 ).

[0050] The base lifting mechanism 39 is configured to lift the base 9 together with the rotating shaft member 15 (and the motor 40). In this embodiment, the lifting drive unit is composed of a cylinder 41 (or an electric cylinder). The front end of the cylinder rod of the cylinder 41 is connected to the base assembly including the rotating shaft member 15 and the motor 40 via the base material BP1.

[0051] Furthermore, in this embodiment, cylinder 41 is composed of a three-position cylinder, which allows the height direction position of the base 9 to be switched between three positions: a first position PP, a second position PS, and a reference position Pm located in between. Additionally, the first position PP of the base 9 is defined as the alignment of the main surface of the substrate W on the base 9 with the upper surface of the preheating ring 32. By aligning the upper surface of the preheating ring 32 with the main surface of the silicon single-crystal substrate W on the base 9, no step difference is generated between the main surface of the substrate W and the preheating ring 32, effectively suppressing disturbances in the flow of raw material gas.

[0052] exist Figure 2 In the reaction vessel body 2, a gas channel 36 is formed on the side of the gas inlet 22. A partition plate 34 is horizontally arranged within the gas channel 36, and the height position of the partition plate 34 is determined so that its front end faces the side of the preheating ring 32 (the periphery of the partition plate 34 can, for example, be fixed to the inner surface of the side wall forming the gas channel 36). The space above the partition plate 34 in the gas channel 36 becomes the raw material gas flow space 5P (see reference). Figure 13The upper channel space 36A is connected. Additionally, the space below the partition plate 34 in the gas channel 36 becomes the lower channel space 36B, which communicates with the instrument configuration space below the preheating ring 32. By setting the aforementioned partition plate 34, as... Figure 13 As shown, the raw material gas G can flow along the main surface of the substrate W in the raw material gas flow space 5P without being disturbed by eddies or other disturbances such as those that flow back from the circumferential side of the preheating ring 32 to its lower side, which can make the thickness of the obtained silicon single crystal film more uniform.

[0053] Furthermore, in this embodiment, such as Figure 2 As shown, the upper surface of the partition plate 34 is aligned with the upper surface of the preheating ring 32. Therefore, no step difference is generated between the preheating ring 32 and the partition plate 34, effectively suppressing disturbances in the raw material gas flow.

[0054] Next, a plurality of lifting pins 13 are provided on the outer periphery of the base 9. The lifting pins 13 lift the substrate W by pushing up the outer periphery of the lower surface of the substrate W from below, and each lower end protrudes downward from the base 9. Specifically, as Figure 4 As shown, multiple through holes 14 for lifting pins are formed at the bottom outer periphery of the countersunk hole 9B in the base 9, extending circumferentially upwards and downwards through the bottom. Figure 5 As shown, the upper end of the lifting pin 13 is made into a head with a diameter larger than that of the base end. Figure 4 The upper end of the insertion hole 14 becomes a countersunk hole with an enlarged diameter to mate with the head of the lifting pin 13. The lower surface of the head of the lifting pin 13 abuts against the bottom surface of the countersunk hole of the insertion hole 14, preventing the lifting pin from falling off the base 9.

[0055] like Figure 2 As shown, a substrate lifting section 20 (finger-shaped wafer lifter) is provided below the preheating ring 32. For example... Figure 5As shown, the substrate lifting unit 20 includes a lifting sleeve 12B and a plurality of lifting pin drive arms 12A connected to the lifting sleeve 12B at the base end. The lifting pin drive arms 12A are arranged corresponding to each lifting pin 13, and a lifting pin force application portion 12C for applying force to the lifting pin 13 from below upwards is formed at the front end. In this embodiment, three lifting pin drive arms 12A are arranged at equal angular intervals around the central axis of the base 9, extending horizontally from the lifting sleeve 12B along the radial direction of the base 9. Furthermore, the width of the lifting pin force application portion 12C forming the front end of each lifting pin drive arm 12A is wider than the portion including the base end of the lifting pin drive arm 12A, and the lifting pin force application portion 12C becomes a lifting plate facing the lower end face of the lifting pin 13 on its lower side. In addition, the lifting sleeve 12B is cylindrical, which allows the rotation drive of the rotating shaft member 15 to be driven and can be raised and lowered coaxially with the outside of the rotating shaft member 15 and along the axis O1 of the rotating shaft member 15, together with the multiple lifting pin drive arms 12A.

[0056] like Figure 2 As shown, the substrate lifting unit 20 is driven by the substrate lifting unit lifting mechanism 12 to move up and down between the rising position PP' and the falling position PS' (in Figure 2 In the diagram, PP' and PS' indicate the positions of the substrate BP2, but in the following description, they are used to indicate the positions of the substrate lifting unit 20. In this embodiment, the lifting drive unit is composed of a cylinder 42 (which may also be an electric cylinder). The front end of the cylinder rod of the cylinder 42 is connected to the lifting sleeve 12B via the substrate BP2.

[0057] When the lifting sleeve 12B approaches the lower surface of the base 9 along the rotating shaft member 15, the lifting pin 13 is forced upward by the lifting pin force application part 12C of the lifting pin drive arm 12A. As a result, the substrate W on the base 9 is lifted from the lower side by the lifting pin 13, making it easy to recover the substrate W after the formation of silicon single crystal.

[0058] The following describes an example of the control method for reaction chamber 1. Figure 6 This is a block diagram showing the electrical structure of the control system of the vapor phase growth apparatus 100. The control system is configured with a control computer 70 as the main control unit. The control computer 70 is constructed by connecting the CPU (Central Processing Unit) 71, the ROM (Read Only Memory) 72 (program storage unit) storing the control program 72a, the RAM (Random Access Memory) 73 which becomes the working memory when the CPU 71 executes the control program 72a, and the input / output unit 74 for electrical input and output of control information via an internal bus 75 (data bus + address bus).

[0059] Figure 1 The driving elements of the reaction chamber 1 shown are connected to the control computer 70 in the following manner. The infrared heating lamp 11 is connected to the input / output unit 74 via the lamp control circuit 11c. Additionally, a thermocouple (temperature sensor) 15B for detecting the substrate temperature is connected to the input / output unit 74. Gas flow regulating instruments 52 and 54 each have a flow detection unit and a built-in valve (not shown), and by connecting to the input / output unit 74, receive instructions from the control computer 70, continuously and variably controlling the raw material gas on each pipeline using the built-in valve.

[0060] The motor 40 of the drive base 9 is connected to the input / output unit 74 via the servo control unit 40c. The servo control unit 40c monitors the rotational speed of the motor 40 and performs drive control with reference to the rotational speed indication value from the control computer 70, so that the rotational speed of the motor 40 (and even the base 9) remains constant.

[0061] Furthermore, the cylinder 41 that drives the lifting of the base 9 is connected to the input / output unit 74 via the cylinder driver 41c, and the cylinder 42 that drives the lifting of the substrate lifting unit 20 is connected to the input / output unit 74 via the cylinder driver 42c. Additionally, the motor 107m (…) drives the handling robot 107… Figure 1 It is connected to the input / output unit 74 via the servo control unit 107c. The servo control unit 107c determines the position of the substrate transport member 105a based on the pulse input from the pulse transmitter 40p (rotation sensor) mounted on the output shaft of the motor 107m, receives drive command information from the control computer 70, and performs drive control.

[0062] The following is for reference Figure 7 Flowcharts and Figures 8-13 The diagram illustrates the operation of the vapor phase growth apparatus 100 controlled by the controlled program 72a. Figure 7 In S101, as control program 72a begins execution, cylinders 41 and 42 ( Figure 6 The action causes the base 9 to move to Figure 8 The reference position Ph shown indicates that the substrate lifting section 20 (finger-shaped wafer lifter: hereinafter, in Figure 7 The base 9 (referred to as "FWL") moves to the rising position PP'. The reference position Ph of the base 9 and the rising position PP' of the substrate lifting part 20 are determined such that the distance between the lower surface of the base 9 and the lifting pin force application part 12C of the substrate lifting part 20 is shorter than the length of the lifting pin 13 protruding from the lower surface of the base 9. As a result, the lifting pin 13 is forcefully pushed upward by the substrate lifting part 20, and becomes a state that protrudes from the upper surface of the base 9. In addition, during this period, according to Figure 1The substrate W is transferred from the loading and locking chamber 104 to the preparation chamber 103 and loaded into the substrate holding part 105H of the substrate conveying member 105a.

[0063] Next, in Figure 7 In S102, by causing cylinders 41 and 42 ( Figure 2 Actions, such as Figure 9 As shown, the base 9 is moved to the second position PS, and the substrate lifting part 20 is moved to the lower position PS'. The base 9 and the substrate lifting part 20 are lowered together so that the lifting pin 13 protrudes from the upper surface of the base 9, thus ensuring a gap, i.e., a substrate loading and unloading space 5T, between the lifting pin 13 and the lower surface of the preheating ring 32 for receiving the substrate transport member 105a.

[0064] In this state, Figure 7 S103 drives cylinder 81 ( Figure 6 ), so that the preparation room gate 108 ( Figure 1 ) becomes the open state. Furthermore, in S104, the drive motor 107m ( Figure 1 This causes the substrate transport member 105a, which is loaded with substrate W, to advance. Thus, as... Figure 10 As shown, the substrate holding portion 105H of the substrate conveying member 105a enters the substrate loading and unloading space 5T together with the substrate W. At this time, gaps are formed between the upper end of the lifting pin 13 and the lower surface of the substrate holding portion 105H, and between the upper surface of the substrate holding portion 105H and the lower surface of the preheating ring 21. In this embodiment, the size of these gaps is set to approximately 3.5 mm.

[0065] Next Figure 7 In S105, cylinders 41 and 42 ( Figure 2 ) work, such as Figure 11 As shown, the base 9 is returned to the reference position Ph, and the substrate lifting part 20 is returned to the raised position PP'. The base 9 and the substrate lifting part 20 are raised together so that the lifting pin 13 protrudes from the upper surface of the base 9. After being raised, the lifting pin 13 abuts against the back side of the substrate W exposed from the substrate holding part 105H, and lifts the substrate W above the substrate holding part 105H.

[0066] Back Figure 7 In S106, drive motor 107m ( Figure 1 ),like Figure 12 As shown, the substrate conveying member 105a retracts after the substrate W has been detached. After the retraction of the substrate conveying member 105a is complete, step S107 is entered, and the driving cylinder 81 ( Figure 6 ), so that the preparation room gate 108 ( Figure 1 ) becomes the closed state. Next, enter S108 to make cylinder 41 ( Figure 2 ) work, such as Figure 13 As shown, only the base 9 is raised to the first position PP. The height position of the substrate lifting part 20 is maintained while the lifting pin 13 is stationary, thereby the upper surface of the base 9 approaches the back surface of the substrate W supported by the upper end of the lifting pin 13, and the substrate W is inserted into the countersunk hole 9B. Figure 4 This results in a situation where the substrate W is mounted on the base 9, and the main surface of the substrate W is aligned with the upper surface of the preheating ring 32. At this time, the height dimension of the raw material gas flow space 5P is ensured to be a relatively small value of 5 mm to 15 mm (approximately 10 mm in this embodiment).

[0067] Next, in S109, the infrared heating lamp 11 is activated to heat the internal space 5 to a set temperature. In S110, the rotation drive of the base 9 is started, and in S111, the flow of the raw material gas is started at a predetermined set flow rate. As a result, a silicon single crystal layer is formed on the substrate W.

[0068] At this time, as Figure 13 As shown, the height dimension of the raw material gas flow space 5P is minimized as described above, thereby increasing the growth rate of the silicon single crystal layer on the substrate W, which is advantageous in terms of improving production efficiency. Furthermore, since the base 9 is close to the infrared heating lamp 11, the heating rate of the substrate W to the target temperature is accelerated, enabling a reduction in heating time. Additionally, increasing the gas filling rate of the raw material gas flow space 5P also contributes to improving the heating rate of the substrate W. If the height dimension of the raw material gas flow space 5P exceeds 15 mm, the effect of increasing the growth rate of the silicon single crystal layer may be insufficient. On the other hand, if the height dimension of the raw material gas flow space 5P is less than 5 mm, the flow resistance of the raw material gas in the raw material gas flow space 5P is excessive, making it difficult to ensure the flow rate of the raw material gas.

[0069] Furthermore, although reaction chamber 1 is configured as a cold-wall type vapor phase growth apparatus, Patent Document 2 discloses that, by increasing the flow rate of the raw material gas, it is possible to suppress the accumulation of silicon deposits, which are reaction products, on the inner wall of the quartz glass forming the reaction vessel body 2 during epitaxial growth. Based on the structure of the present invention, for example... Figure 13In this way, by reducing the height dimension of the set raw material gas flow space 5P, the flow rate of the raw material gas can be increased, which may more effectively suppress the accumulation of silicon deposits on the inner surface of the reaction vessel body 2. For example, in cases where SiH2Cl2 (dichlorosilane S) is used as the silicon source gas and epitaxial growth is carried out at high temperature (e.g., 1150°C) and low pressure (e.g., 60 Torr), the above-mentioned effect is expected to be particularly significant when conditions that easily lead to the accumulation of silicon deposits are adopted.

[0070] Back Figure 7 If film formation is complete, proceed to S112 and stop the rotation of base 9. Additionally, in S113, the flow of raw material gas is stopped. In S114, cylinders 41 and 42 ( Figure 2 The mechanism works to move the base 9 to the reference position Ph, and to move the substrate lifting part 20 to the raised position PP'. This, in turn, becomes... Figure 12 In the same state, the lifting pin 13 rises, and the substrate W after film formation is completed is lifted above the substrate holding part 105H.

[0071] Moreover, in Figure 7 In S115, drive cylinder 81 ( Figure 6 ), so that the preparation room gate 108 ( Figure 1 The motor is in the open state. In S116, the drive motor 107m ( Figure 1 ), causing the empty substrate conveying member 105a to advance (with Figure 11 (Same state). In S117, by making cylinders 41, 42 ( Figure 6 The operation causes base 9 to move to... Figure 2 The second position PS is used to move the substrate lifting part 20 to the lowered position PS'. The base 9 and the substrate lifting part 20 are lowered together so that the lifting pin 13 protrudes from the upper surface of the base 9. In this way, they become integrated with... Figure 10 In the same state, the substrate W after film formation, which is supported by the upper end of the lifting pin 13, is restricted to descend by the substrate holding part 105H and placed on it. On the other hand, the lifting pin 13 disengages downward from the substrate W.

[0072] and, Figure 7 The S118 drives a 107m motor. Figure 1 The substrate conveying member 105a, in which the substrate W is placed, retracts. As a result, the substrate W, which has already formed a film, is returned to the preparation chamber 103. The drive cylinder 81 in S119 ( Figure 6 ), so that the preparation room gate 108 ( Figure 1 It becomes closed.

[0073] The embodiments of the present invention have been described above, but the present invention is not limited thereto. For example, the reaction chamber 1 in the above embodiments is an example of a monolithic apparatus for manufacturing silicon epitaxial wafers by CVD (Chemical Vapor Deposition). When the object to be manufactured is not limited to silicon epitaxial wafers, the present invention can also be applied to an apparatus for epitaxially growing compound semiconductor single crystal layers on single crystal substrates such as agate and silicon by MOVPE (Metal-Oxide Vapor Phase Epitaxy).

[0074] Explanation of reference numerals in the attached figures

[0075] 1 reaction chamber

[0076] 2. Main body of the reaction vessel

[0077] 5. Interior Space

[0078] 5P Raw Material Gas Flow Space

[0079] 5T substrate loading and unloading space

[0080] 7 Discharge pipe

[0081] 9 bases

[0082] 9A Sleeve

[0083] 9B countersunk hole

[0084] 11 Infrared heating lamps

[0085] 12. Lifting mechanism of substrate lifting section

[0086] 12A Lifting Pin Drive Arm

[0087] 12B lifting sleeve

[0088] 12C Lifting Pin Force Application Section

[0089] 13 lifting pins

[0090] 14 through holes

[0091] 15 Rotary Shaft Components

[0092] 15A shaft main body

[0093] 15B thermocouple

[0094] 15C combined pin

[0095] 15D base support arm

[0096] 20 substrate lifting section

[0097] 21 Gas Exhaust Port

[0098] 22 Gas inlet

[0099] 32 preheating ring

[0100] 34 partitions

[0101] 36 gas channels

[0102] 36A Upper Passage Space

[0103] 36B Lower Side Passage Space

[0104] 39 Base Lifting Mechanism

[0105] 40 motors

[0106] 41 and 42 cylinders

[0107] 100 vapor phase growth apparatus

[0108] 105a substrate conveying member

[0109] 105H substrate holding section

[0110] EL silicon single crystal thin film

[0111] EW silicon epitaxial wafers

[0112] PP First Position

[0113] PS Second Position

[0114] O Rotation axis

[0115] PP main surface

[0116] W silicon single crystal substrate.

Claims

1. A vapor-phase growth apparatus for growing semiconductor single-crystal thin films on the main surface of a single-crystal substrate, characterized in that, A reaction vessel body has a gas inlet formed at a first end side in the horizontal direction and a gas outlet formed at a second end side. A single-crystal substrate is horizontally held on a disk-shaped base that is driven to rotate within the internal space of the reaction vessel body. The single-crystal substrate rotates, and a raw material gas for forming a semiconductor single-crystal thin film, introduced into the reaction vessel body from the gas inlet, flows along the main surface of the single-crystal substrate and exits from the gas outlet. A preheating ring is arranged to surround the base. It also has: A base lifting mechanism allows the base to move up and down between a first position and a second position. In the first position, the upper surface of the base is positioned above the lower surface of the preheating ring, and a raw material gas flow space with a predetermined height dimension is formed between the upper surface of the base and the lower surface of the top plate of the reaction vessel body. In the second position, the upper surface of the base is positioned below the lower surface of the preheating ring, and a substrate loading and unloading space with a height dimension larger than the raw material gas flow space is formed between the upper surface of the base and the lower surface of the preheating ring. A substrate conveying member has a substrate holding portion at its front end for loading and unloading the single-crystal substrate in a horizontal manner; and The substrate transport member drive unit reciprocates horizontally between a substrate loading / unloading position and a preparation position relative to the base in the second position. The substrate loading / unloading position is where the substrate holding part is directly above the base, and the preparation position is where the substrate holding part is located within a preparation chamber formed outside the reaction vessel body. The substrate conveying component drive unit is a conveying robot. The conveying robot has multiple robotic arms that form a linkage mechanism. The multiple robotic arms are connected to each other in a manner that allows them to rotate around their respective rotation axes. A motor drives one end of the robotic arm to rotate, thereby driving the robotic arm at the end of the reaction vessel body side that constitutes the substrate conveying component to move forward and backward in the horizontal direction.

2. The vapor phase growth apparatus according to claim 1, wherein, The first position is defined as the height dimension of the raw material gas flow space being between 5 mm and 15 mm.

3. The vapor phase growth apparatus according to claim 1 or 2, wherein, The first position is determined to be that the main surface of the single crystal substrate on the base is aligned with the upper surface of the preheating ring.

4. The vapor phase growth apparatus according to claim 1 or 2, wherein, The flow direction of the raw material gas is determined by designating the side of the reaction vessel body containing the preparation chamber as the first end and the side opposite to the side containing the preparation chamber relative to the rotation axis of the base as the second end. Furthermore, within the internal space of the reaction vessel body, the portion located between the preparation chamber gate and the preheating ring forms a gas passage. The preparation chamber gate can be opened and closed to separate the preparation chambers. A partition plate is horizontally arranged in the gas channel. The height position of the partition plate is determined such that the front end of the plate faces the side of the preheating ring, so that the space above the partition plate in the gas channel becomes the upper channel space that communicates with the raw material gas flow space, and the space below the partition plate in the gas channel becomes the lower channel space that communicates with the instrument configuration space below the preheating ring.

5. The vapor phase growth apparatus according to claim 4, wherein, The upper surface of the partition plate is aligned with the upper surface of the preheating ring.

6. The vapor phase growth apparatus according to claim 1 or 2, wherein, The base is driven to rotate via a rotating shaft member whose upper end is attached to the lower surface of the base, and the base lifting mechanism causes the base and the rotating shaft member to rise and fall together.

7. The vapor phase growth apparatus according to claim 6, wherein, Multiple lifting pins are provided circumferentially on the base such that the lower end protrudes downward from the base. These lifting pins lift the single crystal substrate by pushing up the outer periphery of the lower surface of the single crystal substrate on the base from the lower side. Furthermore, within the reaction vessel body, below the preheating ring, there is a substrate lifting part with lifting pin drive arms and lifting sleeves. Multiple lifting pin drive arms are provided in a manner corresponding to the multiple lifting pins, and a lifting pin force application part is formed at the front end for applying force to the corresponding lifting pin from below. The lifting sleeve allows the rotation drive of the rotating shaft member and is arranged coaxially on the outside of the rotating shaft member in a manner that allows it to move up and down along the axis of the rotating shaft member, and is engaged with the base end of the lifting pin drive arm.

8. A method for manufacturing an epitaxial wafer, characterized in that, The apparatus employs a vapor phase growth device configured to include a reaction vessel body having a gas inlet formed at a first end side in the horizontal direction and a gas outlet formed at a second end side. A single-crystal substrate is horizontally held on a disk-shaped base driven to rotate within the interior space of the reaction vessel body, and the single-crystal substrate rotates. A raw material gas for forming a semiconductor single-crystal thin film, introduced into the reaction vessel body from the gas inlet, flows along the main surface of the single-crystal substrate and exits from the gas outlet. A preheating ring is arranged to surround the base. The apparatus also includes a base lifting mechanism for raising and lowering the base between a first position and a second position. The first position is configured such that the upper surface of the base is positioned above the lower surface of the preheating ring, and the upper surface of the base is positioned above the lower surface of the top plate of the reaction vessel body. A raw material gas flow space with a predetermined height dimension is formed between the base and the preheating ring. The second position is formed such that the upper surface of the base is located below the lower surface of the preheating ring, and a substrate loading / unloading space with a height dimension larger than the raw material gas flow space is formed between the upper surface of the base and the lower surface of the preheating ring. A substrate conveying member has a substrate holding portion at its front end for loading and unloading the single-crystal substrate in a horizontal manner. A substrate conveying member driving portion reciprocates horizontally between the substrate loading / unloading position and the preparation position relative to the base in the second position. The substrate loading / unloading position is where the substrate holding portion is directly above the base, and the preparation position is where the substrate holding portion is located within a preparation chamber formed outside the reaction vessel body. The substrate conveying component drive unit is a handling robot. The handling robot has multiple robotic arms that form a linkage mechanism. The multiple robotic arms are connected to each other in a manner that allows them to rotate about their respective rotation axes. A motor drives one end of the robotic arm to rotate, thereby driving the robotic arm at the end of the reaction vessel body side that constitutes the substrate conveying component to move forward and backward in the horizontal direction. Inside the reaction vessel, with the base in the second position, the single crystal substrate is placed on the base. Then, the base on which the single crystal substrate is placed is raised to the first position, allowing the raw material gas to flow through the reaction vessel, and the semiconductor single crystal thin film is grown epitaxially on the single crystal substrate, thereby obtaining an epitaxial wafer.

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