JP2018060937A - SiC EPITAXIAL WAFER MANUFACTURING METHOD AND SiC EPITAXIAL WAFER MANUFACTURING APPARATUS - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a SiC epitaxial wafer manufacturing method and a SiC epitaxial wafer manufacturing apparatus which improve in-plane uniformity of a thickness of a SiC epitaxial film.SOLUTION: A SiC epitaxial wafer manufacturing method of the present embodiment uses a mounting plate having a concave storage part and a satellite which is arranged in the concave storage part and on which a SiC substrate is placed on an upper surface, in which an etching carrier gas including an etching gas is supplied from a gap between the concave storage part and the satellite to an outer periphery of the SiC epitaxial wafer.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for manufacturing a SiC epitaxial wafer and a manufacturing apparatus for a SiC epitaxial wafer.

  Silicon carbide (SiC) has characteristics such as a dielectric breakdown electric field that is an order of magnitude larger than silicon (Si), a band gap that is three times larger, and a thermal conductivity that is about three times higher. Since silicon carbide has these characteristics, it is expected to be applied to power devices, high frequency devices, high temperature operation devices, and the like. For this reason, in recent years, SiC epitaxial wafers have been used for the above semiconductor devices.

  A SiC epitaxial wafer is manufactured by growing a SiC epitaxial film which becomes an active region of a SiC semiconductor device on a SiC substrate. The SiC substrate is obtained by processing from a SiC bulk single crystal produced by a sublimation method or the like, and the SiC epitaxial film is formed by a chemical vapor deposition (CVD) method.

  As an apparatus for manufacturing a SiC epitaxial wafer, there is known a horizontal rotation / revolution type epitaxial growth apparatus in which a plurality of wafers are arranged horizontally, each wafer is revolved, and the wafer itself is rotated about the center of the wafer. (For example, patent document 1 and patent document 2).

  In this epitaxial growth apparatus, a plurality of satellites are provided on a rotatable mounting plate (susceptor) so as to surround the rotation axis of the mounting plate. When the satellite is allowed to rotate by the rotation drive mechanism, the SiC substrate placed on the satellite is configured to be capable of rotating and revolving by revolving around the rotation axis of the mounting plate and rotating. .

  In the epitaxial growth apparatus as described above, the source gas is supplied onto the SiC substrate by passing the source gas from the outside of the outer peripheral end portion of the SiC substrate placed on the mounting plate. At this time, an epitaxial film is formed by depositing an epitaxial material on the substrate while maintaining the SiC substrate at a high temperature by the heating means.

Japanese Patent No. 2771585 Japanese Patent No. 2835338

  Here, when the SiC epitaxial film is grown on the SiC substrate, there is a problem that the film thickness increases in the outer peripheral portion of the obtained SiC epitaxial film, that is, near the edge, and the carrier concentration decreases. In particular, this tendency is remarkable when a SiC epitaxial film is grown on a large SiC substrate in order to obtain a large SiC epitaxial wafer such as 4 inches or 6 inches. With the strong demand from the market in recent years for increasing the size of SiC epitaxial wafers, it is required to increase the uniformity in the in-plane direction of the SiC epitaxial film thickness and carrier concentration. The in-plane uniformity of the film thickness and carrier concentration can be controlled to some extent by the temperature distribution of the reactor used for film formation, the supply conditions of the raw material gas, etc., but there are limitations. In particular, when the distribution is such that the carrier concentration and the film thickness change locally at the periphery of the wafer, it is difficult to control this.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an SiC epitaxial wafer manufacturing method and an SiC epitaxial wafer manufacturing apparatus that improve the in-plane uniformity of the film thickness of the SiC epitaxial film.

  As a result of the study, the inventors of the present invention have formed SiC by supplying a carrier gas containing an etching gas (referred to as an etching carrier gas) from a predetermined position to a SiC substrate during or after film formation. It has been found that the thickness of the epitaxial film can be controlled. In addition, a structure of an SiC epitaxial wafer manufacturing apparatus capable of efficiently controlling the thickness of a predetermined portion of the formed SiC epitaxial film without making a significant change to an existing apparatus was found, and the invention was completed. I let you. That is, this invention provides the following procedures in order to solve the said subject.

(1) An SiC epitaxial wafer manufacturing method according to an aspect of the present invention uses a mounting plate having a concave housing portion and a satellite disposed in the concave housing portion and on which an SiC substrate is placed on the upper surface. In the method for manufacturing an epitaxial wafer, an etching carrier gas containing an etching gas is supplied to the outer periphery of the SiC epitaxial wafer from between the concave housing portion and the satellite.
(2) In the method of manufacturing an SiC epitaxial wafer described in (1) above, HCl gas may be used as the etching gas.
(3) In the method for manufacturing an SiC epitaxial wafer according to any one of (1) and (2), a doping carrier further including a doping gas on the outer periphery of the SiC epitaxial wafer from between the concave accommodating portion and the satellite Gas may be supplied.
(4) A SiC epitaxial wafer manufacturing apparatus according to an aspect of the present invention is a SiC epitaxial wafer manufacturing apparatus for growing a SiC epitaxial film on a main surface of a SiC substrate by a chemical vapor deposition method. A mounting plate having a housing portion, a satellite disposed in the concave housing portion and on which a SiC substrate is placed, and a raw material gas for an SiC epitaxial film on the main surface of the SiC substrate placed on the top surface of the satellite And a second gas supply pipe for supplying an etching carrier gas containing an etching gas in the concave housing portion.

  By using the SiC epitaxial wafer manufacturing method and manufacturing apparatus of the present invention, an etching gas is locally supplied to the outer peripheral portion of the SiC epitaxial film during or after film formation by epitaxial growth. Thereby, the SiC epitaxial film of the outer peripheral part formed epitaxially and thicker than the center part can be etched. Therefore, by adjusting the etching amount, the thickness of the outer peripheral portion of the SiC epitaxial film to be formed can be made equal to the thickness of the central portion, and consequently the in-plane uniformity of the thickness can be improved.

It is a cross-sectional schematic diagram of the manufacturing apparatus of the SiC epitaxial wafer which concerns on 1 aspect of this invention. It is the figure which planarly viewed the mounting plate in the manufacturing apparatus of the SiC epitaxial wafer concerning one Embodiment of this invention. It is the cross-sectional schematic diagram which expanded the one satellite periphery in the manufacturing apparatus of the SiC epitaxial wafer concerning one Embodiment of this invention.

Hereinafter, a SiC epitaxial wafer manufacturing method and a manufacturing apparatus to which the present invention is applied will be described in detail with reference to the drawings as appropriate.
In the drawings used in the following description, in order to make the characteristics of the present invention easier to understand, the characteristic parts may be shown in an enlarged manner for the sake of convenience, and the dimensional ratios of the respective components are different from actual ones. Sometimes. In addition, the materials, dimensions, and the like exemplified in the following description are examples, and the present invention is not limited to them, and can be appropriately changed and implemented without changing the gist thereof.

First, the definition about the name of the gas in this specification is demonstrated. A gas that supplies an element constituting SiC (silicon carbide) is referred to as “source gas”. The source gas includes a silane-based gas and a hydrocarbon-based gas. As the silane-based gas, silane (SiH ₄ ), dichlorosilane (SiCl ₂ H ₂ ), trichlorosilane (SiCl ₃ ), silicon tetrachloride (SiCl ₄ ), or the like can be used. Propane (C ₃ H ₈ ), ethane (C ₂ H ₆ ), or the like can be used as the hydrocarbon gas. In addition to these source gases, a gas containing a carrier gas, which will be described later, may be described as a “source gas” in a broad sense.

  In addition to the main source gas which is a constituent element of silicon carbide, a gas for performing doping is referred to as “dopant gas”. What is doped in the SiC substrate by this dopant gas functions as a carrier in the SiC substrate. Examples of the dopant gas for silicon carbide include nitrogen and ammonia for N-type doping, and trimethylaluminum for P-type doping.

A gas having a function of carrying a source gas or a doping gas, which is flowed in a larger amount than the source gas in CVD crystal growth, is called “carrier gas”. Examples of the carrier gas include argon (Ar) and hydrogen (H ₂ ). That is, the “carrier” of the “carrier gas” is not the same as the “carrier” of the “carrier density (concentration)” in the SiC substrate.
The “dopant carrier gas” means a gas containing a dopant gas, and includes a gas in which a dopant gas and a carrier gas are mixed. For example, the dopant carrier gas may be composed of only nitrogen gas, or may be a mixture of nitrogen gas and rare gas.

  The “etching carrier gas” described below means a gas containing an etching gas such as hydrogen chloride (HCl) gas, and also includes a gas in which an etching gas and a carrier gas are mixed. The etching gas is a gas that reacts with SiC at high temperature and has an etching action, and examples thereof include a halide compound, and excludes hydrogen that is generally used as a carrier gas.

<SiC epitaxial wafer manufacturing equipment>
In order to facilitate understanding of the configuration, the SiC epitaxial wafer manufacturing apparatus will be described. FIG. 1 is a diagram schematically illustrating a cross section of a SiC epitaxial wafer manufacturing apparatus according to an embodiment of the present invention.

  An SiC epitaxial wafer manufacturing apparatus 100 according to an embodiment of the present invention includes a mounting plate 10, a satellite 20, a first gas supply pipe 30, a second gas supply pipe 40, and a gas supply unit (not shown). Have. The SiC epitaxial wafer manufacturing apparatus 100 includes a sealing 50 and a side wall 60 for forming the reaction space K, and a heater 70 for heating the reaction space K. In SiC epitaxial wafer manufacturing apparatus 100, source gas G is supplied into a chamber (deposition chamber) that can be evacuated under reduced pressure, and an SiC epitaxial film is grown on the surface of heated SiC substrate W. The source gas G supplied into the chamber (film formation chamber) may be a source gas in a broad sense.

  FIG. 2 is a plan view of the mounting plate in the SiC epitaxial wafer manufacturing apparatus according to one embodiment of the present invention. The mounting plate 10 includes a turntable 13 having a circular shape in plan view and a rotating shaft 12 connected to the center of the turntable 13. The turntable 13 is provided with a plurality of concave accommodating portions 11 arranged at equal intervals in the circumferential direction (rotation direction) of the turntable 13. In FIG. 2, the case where the six recessed accommodating parts 11 are provided in a line at equal intervals is illustrated. For the sake of simplicity, the satellite 20 is accommodated only in one concave accommodating portion 11 of the mounting plate 10, but the configuration is not limited thereto.

A rotating shaft 12 is attached to the lower center of the mounting plate 10. When the rotary shaft 12 is rotated by a drive motor (not shown), the rotary base 13 can be driven to rotate around its central axis. Hereinafter, the rotation about the rotation axis 12 may be referred to as “revolution”.
The mounting plate 10 only needs to have heat resistance, and is made of a known material such as graphite, TaC-coated graphite, SiC-coated graphite, or the like.

FIG. 3 is an enlarged schematic cross-sectional view of the vicinity of one satellite 20 in the SiC epitaxial wafer manufacturing apparatus according to one embodiment of the present invention.
The satellite 20 is accommodated in the concave accommodating portion 11 of the mounting plate 10. The satellite 20 can be rotated by the rotation driving means inside the concave accommodating portion 11. That is, the satellite 20 can revolve with respect to the rotating shaft 12. The material of the satellite 20 can be the same material as the mounting plate 10.

  It is preferable that the outer diameter of the satellite 20 and the inner diameter of the concave accommodating portion 11 are substantially the same size, and the concave accommodating portion 11 is slightly larger. If the size of the concave accommodating portion 11 is too large compared to the satellite 20, the satellite 20 is liable to skid in the concave accommodating portion 11 when the satellite 20 rotates. In that case, it becomes difficult to obtain a uniform SiC epitaxial film. On the other hand, if the outer diameter of the satellite 20 and the inner diameter of the concave housing portion 11 are the same, it is impossible to secure a sufficient flow path for the gas supplied from the second gas supply pipe 40 described later.

  An SiC substrate W is placed on the satellite 20. As shown in FIG. 3, the SiC substrate W is preferably placed in a recess 21 formed in the upper surface 20 a of the satellite 20. By placing SiC substrate W in recess 21, it is possible to prevent SiC substrate W from slipping due to rotation or the like.

  The mounting surface of the satellite 20 on the SiC substrate is preferably circular. When the orientation flat (OF) is provided on the SiC substrate W, the placement surface may have a straight line portion similar to the SiC substrate W and corresponding to the OF. This is to prevent unnecessary crystals from being deposited by reducing the portion not covered by the SiC substrate W. If there is a portion that is not covered with the SiC substrate W on the mounting surface of the satellite 20, the SiC substrate W may float with respect to the mounting surface because crystals are deposited on the portion.

  The upper surface (surface to be processed) of SiC substrate W placed on satellite 20 is preferably on the same plane as turntable upper surface 13a or on the lower side. When the SiC substrate W is on the upper side of the turntable upper surface 13a, disturbance of the flow of the source gas (turbulence of laminar flow) is likely to occur at the end of the SiC substrate W. If the flow of the source gas is disturbed, there may be a difference between the characteristics of the film formed at the end of the SiC substrate W and the characteristics of the film formed at the center.

  The first gas supply pipe 30 has a first end connected to a gas supply (not shown) (external tank), and a second end surrounded by the sealing 50, the side wall 60, and the mounting plate 10. It is connected to the. The source gas G can be supplied to the reaction space K by the first gas supply pipe 30. As the source gas G, a gas containing a hydrocarbon-based gas and a silane-based gas that are generally used as a source of the SiC epitaxial film can be used. As the hydrocarbon-based gas and the silane-based gas, those described above can be used. A carrier gas and a dopant gas may be supplied from the first gas supply pipe 30 simultaneously with the source gas.

  As shown in FIG. 1, the second end portion (reaction space side supply port) of the first gas supply pipe 30 is preferably provided at a position facing the center of the mounting plate 10. Since the supply port of the first gas supply pipe 30 is provided facing the center of the mounting plate 10, the flow of the source gas supplied from the first gas supply pipe 30 is directed from the center of the mounting plate 10 to the outer periphery. Can be controlled. That is, the source gas can be supplied uniformly to the satellite 20 placed on the mounting plate 10.

  The second gas supply pipe 40 has a first end connected to a gas supply unit (external tank) (not shown) and the like, and a second end connected to the concave accommodating portion 11. The gas supply unit may use a tank containing an etching carrier gas. Alternatively, a gas mixing device that mixes a carrier gas such as hydrogen and an etching gas at a controlled flow rate can be used as the gas supply unit. The gas mixing device mixes a carrier gas and an etching gas at a certain ratio, and supplies part or all of the mixed gas to the second gas supply pipe at a predetermined flow rate and pressure. Or the like. In FIG. 1, the second gas supply pipe 40 is formed so as to penetrate through the rotary shaft 12 and the rotary base 13 of the mounting plate 10, and has a supply port 41 on the upper surface 11 a of the concave housing portion.

  The second gas supply pipe 40 has a supply port 41 on the upper surface 11a of the concave housing portion. Therefore, when the satellite 20 is accommodated in the concave accommodating portion 11, gas is supplied between the lower surface 20 b of the satellite 20 and the concave accommodating portion 11. The satellite 20 floats slightly from the upper surface 11a of the concave housing portion due to the gas supplied from the supply port 41. Therefore, the frictional force applied between the concave accommodating portion 11 and the satellite 20 is reduced, and the satellite 20 is rotatable about its center. By rotating the satellite 20 around the central axis, film formation can be performed uniformly on the SiC substrate W placed on the satellite 20.

The rotation of the satellite 20 may be configured to be controlled by the gas discharged from the supply port 41. The gas discharged from the supply port 41 has a function of floating the satellite 20 and a function of rotating it.
For example, by forming a spiral groove on the bottom surface of the concave accommodating portion 11 and guiding the gas to flow along the groove, torque is applied to the satellite 20 due to the viscosity of the gas, and this can be rotated. it can.
Alternatively, even if a spiral groove is formed on the back side of the satellite 20 and the gas is guided to flow along the groove, it can be rotated in the same manner. That is, it is not necessary to separately prepare driving means having an external power source or the like in order to rotate the satellite 20, and the configuration of the SiC epitaxial manufacturing apparatus becomes simple.

  As described above, the gas supplied from the supply port 41 has a function of floating the satellite and a function of rotating the satellite. The number of supply ports 41 is not limited. For example, as shown in FIG. 3, one supply port 41 may be provided, and both the gas to be floated and the gas to be rotated may be supplied, or two supply ports 41 are provided and the gas to be floated from one of them is supplied. A gas that is supplied and rotated from the other side may be supplied. The etching carrier gas may be supplied from either a gas supply port for levitation or a gas supply port for rotation.

  The second gas supply pipe 40 supplies an etching carrier gas containing an etching gas to the reaction space K from an external tank (not shown). The etching carrier gas supplied from the second gas supply pipe 40 is supplied to the reaction space K via the space between the concave accommodating portion 11 and the satellite 20 as shown in FIG. That is, the etching carrier gas is supplied from the outer periphery toward the center of the SiC substrate W placed on the satellite 20. Therefore, the etching amount of the outer peripheral portion of SiC substrate W can be increased with respect to the etching amount of the central portion.

  The ceiling 50 is disposed so as to cover the mounting plate 10 and the satellite 20 from above. The ceiling 50 is also a disk-like member formed by coating the surface of a base material made of graphite, like the mounting plate 10 and the satellite 20. The coating film for coating the surface of the sealing 50 can be formed using conventionally known TaC, SiC, or the like.

  The side wall 60 is made of a known material. For example, a support portion 61 may be provided as shown in FIG. The support part 61 is a sealing support part provided on the inner peripheral surface of the side wall 60 over the entire periphery, and the outer peripheral part of the sealing 50 can be placed on the sealing support part. Gas that is no longer necessary in the chamber can be discharged out of the chamber through an exhaust port provided between the side wall 60 and the mounting plate 10.

  The heater 70 heats the reaction space K. For example, an induction coil or the like can be used as the heater 70. When a high frequency current is supplied from a high frequency power supply (not shown) to the induction coil, the mounting plate 10 and the ceiling 50 are heated by high frequency induction heating. The SiC substrate W placed on the satellite 20 can be heated by radiation from the heated mounting plate 10 and the ceiling 50, heat conduction from the satellite 20, or the like. The heating means is not limited to the configuration disposed on the lower surface side of the mounting plate 10 (the turntable 13) and the upper surface side of the ceiling 50, and may be configured to be disposed only on either one of these. is there. In addition, the heater 70 is not limited to high-frequency induction heating, but may be resistance heating.

  By using the SiC epitaxial wafer manufacturing apparatus 100 according to the present embodiment, an etching gas is locally supplied to the outer peripheral portion of the SiC epitaxial film during or after film formation by epitaxial growth. Thereby, the SiC epitaxial film of the outer peripheral part formed thicker than a center part by epitaxial growth can be etched. Therefore, by adjusting the etching amount, the thickness of the outer peripheral portion of the SiC epitaxial film to be formed can be made equal to the thickness of the central portion, and consequently the in-plane uniformity of the thickness can be improved.

  The growth amount of the epitaxial layer is the difference between the amount of the raw material on the gas side taken into the epi growth surface and the amount of SiC on the epi growth surface removed to the gas side. In the epi surface portion where the etching gas is flown, atoms on the surface of the SiC epi layer react with the etching gas, thereby increasing the amount of surface SiC removed to the gas side. Further, in the gas side portion where the etching gas is flowed, the gas side raw material near the wafer surface is reduced by reacting with the etching gas, and the amount of the gas side raw material taken into the growth surface is also reduced. These effects are combined, and the growth amount of the epitaxial film is locally reduced at the outer peripheral portion to which the etching gas is supplied.

  Since the etching gas can be supplied to the outer peripheral portion of the SiC epitaxial film without significantly changing the existing apparatus, the in-plane uniformity of the thickness of the SiC epitaxial film can be improved inexpensively and easily. Can be realized.

<SiC epitaxial wafer manufacturing method>
A method for producing a SiC epitaxial wafer according to the present invention is a method for producing a SiC epitaxial wafer comprising: a mounting plate having a concave housing portion; and a satellite disposed in the concave housing portion and on which a SiC substrate is placed. An etching carrier gas containing an etching gas such as hydrogen chloride (HCl) is supplied from between the concave housing portion and the satellite to the outer periphery of the SiC epitaxial wafer.
A method of manufacturing an SiC epitaxial wafer will be described by taking as an example the case of using the SiC epitaxial wafer manufacturing apparatus 100 of FIG.

  First, an SiC substrate W to be placed on the satellite 20 is prepared. The SiC substrate W can be obtained by slicing a SiC single crystal ingot into a disk shape with a wire saw or the like. Moreover, you may chamfer the outer peripheral part. At this time, the SiC bulk single crystal growth method, the ingot grinding method, the slicing method, and the like are not particularly limited, and a conventionally known method can be employed.

  Next, the obtained SiC substrate W is polished. A conventionally known method can be adopted as a polishing method. It is preferable to perform both rough polishing and mirror polishing. Rough polishing can be performed using, for example, a mechanical polishing method such as lapping. By rough polishing, it is possible to remove irregularities such as large waviness and processing strain in the SiC substrate W. The mirror polishing can be performed by, for example, a CMP method. In the mirror polishing, the flatness of the SiC substrate whose irregularities and parallelism are adjusted by rough polishing can be further increased.

Next, a SiC epitaxial film is grown on the obtained SiC substrate W.
First, the SiC substrate W is placed on the satellite 20 of the SiC epitaxial wafer manufacturing apparatus 100 described above.

  After placing the SiC substrate W, the reaction space K is evacuated by a vacuum pump (not shown), and a gas such as hydrogen or argon is supplied from the first gas supply pipe 30 to be in a certain decompression state. Further, the reaction space K is heated by the heater 70. Further, the rotary shaft 12 is driven to rotate by a drive motor (not shown) and the satellite 20 is revolved. The rotation of the satellite 20 is preferably performed by the gas supplied from the second gas supply pipe 40. By using the gas supplied from the second gas supply pipe 40, it is possible to avoid complication of the apparatus. The satellite 20 revolves around the rotating shaft 12.

  In this state, the source gas G is further supplied from the first gas supply pipe 30. The source gas G supplied to the reaction space K spreads from the center of the mounting plate 10 toward the outer periphery, passes through the space between the mounting plate 10 and the side wall 60 and is discharged to the outside. At this time, in the SiC substrate W placed on the satellite 20, the silane-based gas and the hydrocarbon-based gas in the source gas react to grow an SiC epitaxial film. Further, by mixing a dopant gas with the source gas G, a SiC epitaxial film containing a dopant element contributing as a semiconductor dopant can be grown.

  The gas supplied from the second gas supply pipe 40 is supplied to the reaction space K via the space between the concave accommodating portion 11 and the satellite 20. Therefore, the gas supplied from the second gas supply pipe 40 is supplied from the outer periphery toward the center with respect to the SiC substrate W. Therefore, by including an etching gas in the gas supplied from the second gas supply pipe 40, the etching amount of the outer peripheral portion with respect to the central portion of the epitaxially grown SiC epitaxial film can be increased.

  The total amount of gas supplied from the second gas supply pipe 40 relative to the total amount of gas supplied from the first gas supply pipe 30 is preferably 1/300 to 1/50. By reducing the total amount of gas supplied from the second gas supply pipe 40 in comparison with the total amount of gas supplied from the first gas supply pipe, the gas flow in the chamber can be reduced to the center of the mounting plate 10. It can control so that the direction which goes to an outer periphery may become main, and generation | occurrence | production of a turbulent flow etc. can be suppressed.

  The above has been described with the self-revolving epitaxial growth apparatus. However, the configuration is limited to the self-revolving epitaxial growth apparatus as long as it includes a configuration in which a dopant carrier gas containing a dopant gas is supplied to the outer periphery of the SiC epitaxial wafer from between the concave housing portion and the satellite. Is not to be done. For example, an apparatus that only rotates the wafer may be used, or an apparatus that only revolves the satellite by an apparatus that only rotates.

  By using the SiC epitaxial wafer manufacturing method according to the present embodiment, an etching gas is supplied to the outer peripheral portion of the SiC epitaxial film during or after film formation by epitaxial growth. Thereby, the SiC epitaxial film of the outer peripheral part formed epitaxially and thicker than the center part can be etched. Therefore, by adjusting the etching amount, the thickness of the outer peripheral portion of the SiC epitaxial film to be formed can be made equal to the thickness of the central portion, and consequently the in-plane uniformity of the thickness can be improved.

  A dopant carrier gas containing a dopant gas such as nitrogen may be supplied from the second gas supply pipe 40 together with the etching carrier gas. In this case, together with the etching carrier gas, the dopant carrier gas is supplied to the reaction space K via the space between the concave accommodating portion 11 and the satellite 20, and then supplied from the outer periphery of the SiC substrate W toward the center.

  Therefore, the etching amount of the outer peripheral portion of SiC substrate W can be increased with respect to the etching amount of the central portion, and the carrier supply amount of the outer peripheral portion of SiC substrate W can be increased with respect to the supply amount of the central portion. Therefore, if the etching amount and the carrier supply amount are adjusted, the film thickness and carrier concentration of the outer peripheral portion of the SiC epitaxial film to be formed can be made uniform with the central portion. Can be improved together.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific embodiments, and various modifications can be made within the scope of the gist of the present invention described in the claims. Can be modified or changed.

  Since the SiC epitaxial wafer manufacturing apparatus of the present invention can manufacture a SiC epitaxial wafer having excellent electrical characteristics with a simple apparatus with high productivity, for example, a SiC epitaxial wafer used for a power device, a high-frequency device, a high-temperature operating device, etc. Can be manufactured.

DESCRIPTION OF SYMBOLS 10 ... Mounting plate, 11 ... Concave accommodation part, 11a ... Upper surface, 12 ... Rotating shaft, 13 ... Turntable,
13a: Turntable upper surface, 14 ... Groove, 20 ... Satellite, 20a ... Upper surface, 20b ... Lower surface, 21
DESCRIPTION OF SYMBOLS ... Recessed part 30 ... 1st gas supply pipe | tube, 40 ... 2nd gas supply pipe | tube, 41 ... Supply port, 50 ... Sealing, 60 ... Side wall, 61 ... Support part, 70 ... Heater, 100 ... Manufacturing apparatus of SiC epitaxial wafer, G ... Raw material gas, K ... Reaction space, W ... SiC wafer

Claims (4)

A method for producing an SiC epitaxial wafer using a mounting plate having a concave accommodating portion and a satellite disposed in the concave accommodating portion and on which an SiC substrate is placed.
An SiC epitaxial wafer manufacturing method, comprising: supplying an etching carrier gas containing an etching gas to an outer periphery of the SiC epitaxial wafer from between the concave housing portion and the satellite.   The method of manufacturing an SiC epitaxial wafer according to claim 1, wherein HCl gas is used as the etching gas.   3. The SiC epitaxial wafer production according to claim 1, wherein a doping carrier gas further containing a doping gas is supplied to the outer periphery of the SiC epitaxial wafer from between the concave housing portion and the satellite. Method. A SiC epitaxial wafer manufacturing apparatus for growing a SiC epitaxial film by chemical vapor deposition on a main surface of a SiC substrate,
A mounting plate having a concave receiving portion;
A satellite disposed in the concave accommodating portion and on which an SiC substrate is placed;
A first gas supply pipe for supplying a raw material gas of the SiC epitaxial film to the main surface of the SiC substrate placed on the upper surface of the satellite;
A SiC epitaxial wafer manufacturing apparatus, comprising: a second gas supply pipe that supplies an etching carrier gas containing an etching gas into the concave housing portion.

Images