JP2012129360A - Processing method of susceptor base material and susceptor base material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a processing method of a susceptor base material in which a cutting mark does not appear at a part where a wafer is mounted, and to provide a susceptor base material.SOLUTION: In the processing method of a susceptor base material 11 using a rotary blade for cutting, axial end of the rotary blade 15 has a round shape. The rotary blade 15 performs cutting of the susceptor base material 11 while inclining a predetermined angle against the normal 23 to the upper surface of the susceptor base material 11. A processed surface 27 thus formed has thereby no cutting mark in a recess of the susceptor base material 11 where cutting is performed.

Description

  The present invention relates to a susceptor base material processing method and a susceptor base material.

  A portion (wafer pocket) on which a wafer of a susceptor base material made of graphite is placed is formed by a processing method such as cutting or grinding (for example, Patent Document 1). Conventionally, as shown in FIG. 6, when the wafer pocket 503 formed on the susceptor base 501 is a curved surface, (1) a method of moving the cutter along the curved surface, and (2) the blade surface corresponds to the workpiece surface. A method using a cutting tool formed in a curved shape, and (3) a method in which the above (1) and (2) are combined are used as a processing method. The processing method (1) can be performed while controlling the height of the blade 505 such as a ball end mill with a three-axis NC processing machine in the X direction, the Y direction, and the Z direction. Moreover, the processing method of (2) can be made into the target curved surface only by controlling the height of a cutter.

Japanese Patent Laid-Open No. 2004-200436

  By the way, in a conventional machining method in which machining is performed while controlling the height of the cutter with a three-axis NC machine, a cutting mark (tool mark) is formed. This tool mark remains even if a SiC film is formed on the susceptor substrate 501 in a later step. Therefore, when such a susceptor base material is used during the epitaxial growth of Si, SiC, a compound semiconductor, etc., there is a problem that residual tool marks (cut marks) are transferred to the wafer. In addition, the conventional processing method of processing with a cutter having a predetermined curve (curve) specified in advance is suitable for mass production of one shape, but it is gradually processed due to wear of the cutter. There is a problem that an error from the design value of the shape becomes large. Therefore, in order to reduce the error of the machining shape, it is necessary to replace the blade, and the equipment cost for the grinding process increases.

  The present invention has been made in view of the above situation, and an object of the present invention is to provide a method for processing a susceptor base material and a susceptor base material in which a cutting trace is not formed on a portion on which a wafer is placed.

The above object of the present invention is achieved by the following configuration.
(1) A method of processing a susceptor base material that performs a cutting process using a rotary cutter, wherein a shaft tip of the rotary cutter has an R shape, and the rotary cutter has a normal to an upper surface of the susceptor base. A method of processing a susceptor base material, wherein the susceptor base material is cut at a predetermined angle, and a processed surface having no cutting trace is formed in a concave portion in which the susceptor base material is cut.

  According to this method of processing a susceptor base material, the rotary blade is inclined with respect to the normal line of the upper surface of the susceptor base material, so that the non-cutting point at the cutting speed “0”, that is, the rotation of the rotary blade without processing ability is rotated. The center touches the machining surface and does not move, and cutting traces are not formed on the machining surface.

(2) The susceptor base material has a concave portion on which a wafer is placed, and the rotary blade cuts the graphite material spirally around the central axis of the concave portion. Processing method of susceptor substrate.

  According to this susceptor base material processing method, the processing surface of the concave portion that is a circular surface can be continuously cut while the rotary blade is in contact, and the stepped portion by the rotary blade being separated and recontacted, etc. Does not occur on the machined surface, so no cutting marks are generated.

(3) The susceptor base material processing method according to (2), wherein the rotary blade is cut from the center of the concave portion of the susceptor base material toward the outer periphery.

  According to this susceptor base material processing method, since cutting is performed spirally from the center of the susceptor base material toward the outer periphery, small protrusions remaining during processing and at the completion of the cutting processing are not formed. Therefore, the dent due to the drop-off of the protrusion cannot be formed, and the processing surface can be chipped or processed without difficulty.

(4) The method for processing a susceptor base material according to (3), wherein the cutting is down-cut processing.

  According to this susceptor base material processing method, since the moving direction of the blade due to the rotating blade rotating at a high speed is opposite to the moving direction of the rotary blade itself, the processing surface of the susceptor base material is peeled off. Therefore, a smooth processed surface can be obtained. The peeling process will be described later with reference to FIG.

(5) The method of processing a susceptor base material according to (4), wherein the movement of the susceptor base material is rotation about the center of the susceptor base material.

  According to this susceptor base material processing method, cutting can be performed continuously with the rotary blade in contact with the susceptor base material.

(6) The method for processing a susceptor substrate according to any one of (1) to (5), wherein a predetermined angle with respect to a normal line of the upper surface of the susceptor substrate of the rotary blade is 20 to 70 degrees. .

  According to this susceptor base material processing method, when the angle of inclination of the rotary blade with respect to the normal of the upper surface of the susceptor base material exceeds 70 degrees, the susceptor base material and the cutting machine easily interfere with each other. Since the radial load component perpendicular to the rotation axis applied to the rotary blade is increased, the rotary blade is bent and machining accuracy cannot be obtained. Further, when the angle of inclination of the rotary blade with respect to the normal line of the upper surface of the susceptor base material is less than 20 degrees, a glossy susceptor base material is easily formed.

(7) The method of processing a susceptor substrate according to any one of (1) to (6), wherein the shape of the recess is a curved bottom surface of the recess.

  According to this susceptor base material processing method, since the bottom surface of the concave portion of the susceptor base material is a curved surface, when the wafer is placed in the concave portion of the susceptor base material and the film formation process is performed, the wafer is thermally deformed. In addition, since the distance between the susceptor substrate and the wafer can be reduced, a susceptor capable of transferring heat uniformly from the susceptor to the wafer can be obtained.

(8) The method for processing a susceptor base material according to (7), wherein the bottom surface of the concave portion is a convex curved surface.

  According to this susceptor base material processing method, since the bottom surface of the concave portion of the susceptor base material has a convex curve, a compound semiconductor wafer whose top surface is deformed in a convex direction is placed on the concave portion of the susceptor base material. When the film processing is performed, the distance between the susceptor substrate and the wafer can be reduced even if the wafer is thermally deformed, so that a susceptor capable of uniformly transferring heat from the susceptor to the wafer can be obtained.

(9) The method for processing a susceptor base material according to (7), wherein the bottom surface of the concave portion has a shape similar to a warp generated when the wafer is processed.

  According to this susceptor base material processing method, since the bottom surface of the concave portion of the susceptor base material having a shape similar to the warpage of the processed wafer is formed, the wafer processing processing causes warpage deformation of the wafer. In addition, the deformed wafer shape can be reliably supported by the bottom surface of the concave portion of the susceptor base material. Therefore, a susceptor that can transfer heat uniformly from the susceptor to the wafer can be obtained.

(10) The method for processing a susceptor substrate according to any one of (2) to (9), wherein a plurality of recesses are formed corresponding to the plurality of wafers.

  According to this susceptor base material processing method, since the concave portions are formed on the plurality of wafers, the plurality of concave portions can be sequentially cut while rotating one susceptor base material.

(11) A susceptor base material processed by the processing method of any one of (1) to (10).

  According to this susceptor base material, since there is no cutting trace in the portion where the wafer is placed, temperature unevenness due to the difference in thermal emissivity depending on the surface state does not occur in the wafer. Therefore, a wafer manufactured using this susceptor has a small variation in film forming temperature, and a wafer having no variation in characteristics of a semiconductor product to be cut out can be manufactured.

  According to the susceptor base material processing method of the present invention, it is possible to obtain a susceptor base material processing method and a susceptor base material in which cutting marks are not formed on a portion on which a wafer is placed.

  According to the susceptor substrate according to the present invention, the difference in thermal emissivity due to the cutting trace can be suppressed, and unevenness of the wafer temperature can be prevented.

It is the schematic diagram which represented the part by which the wafer cut by the processing method of the susceptor base material which concerns on this invention was mounted with the rotary blade. It is a principal part enlarged view of FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram of the processing method of the susceptor base material which concerns on this invention, (a) The top view showing the relationship between the rotation direction of a rotary blade, and the moving direction of the processing surface of a susceptor base material, (b) is the side surface FIG. It is a schematic diagram of the processing method of the susceptor base material which concerns on this invention, (a) is PP sectional drawing of Fig.3 (a), The figure explaining downcut processing, (b) is FIG.3 (a). It is a figure explaining an up cut process by PP cross section. It is a schematic diagram of the processing method of the susceptor base material which concerns on this invention, (a) is a side view which shows an example of a 5-axis processing machine, (b) is a front view of (a). It is the schematic diagram showing the susceptor base material cut by the conventional processing method, and its processing condition.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic view showing a portion on which a wafer cut by the susceptor base material processing method according to the present invention is placed together with a rotary blade, and FIG. 2 is an enlarged view of a main part of FIG. FIG. 3 is a schematic view of a processing method of a susceptor base material according to the present invention, and FIG. 3A is a plan view showing the relationship between the rotational direction and moving direction of the rotary blade and the moving direction of the susceptor base material. ) Is a side view thereof.
The processing method of the susceptor base material 11 according to the present embodiment uses a rotary blade 15 having a shaft tip 13 having an R shape. For the rotary blade 15, for example, a ball end mill suitable for cutting the curved surface 17 can be used. In addition to the ball end mill, a radius end mill having a rounded corner can be used for processing. The rotary blade 15 is provided with a blade on an R-shaped circumference. The relationship between the “rake angle” and “flank angle” of each blade is the same as that of a lathe tool. In the R shape, it is only necessary that the cutting part of the rotary cutter forms a convex curved surface when rotated about the central axis. For example, outside the ball end mill having a radius of 0.1 to 3 mm of the cutting part, the cutting part A radius end mill having a radius of curvature of 0.1 to 3 mm can be used. Further, the radius of curvature of the cutting portion may not be constant, and may be an R shape that is connected continuously or stepwise.

  The rotary blade 15 is cut by being inclined at a predetermined angle θ with respect to the normal line 23 of the upper surface 21 of the susceptor base material 11, and the recess 25 where the susceptor base material 11 is cut has no cutting marks. Surface 27 is formed. The predetermined angle θ of the rotary blade 15 is a relative angle, and the susceptor base material 11 may be inclined as shown in the drawing with the rotary shaft 29 in the vertical direction. In the processing method of the susceptor base material 11, the rotating blade 15 is inclined with respect to the normal line 23 of the upper surface 21 of the susceptor base material 11, so that the non-cutting point 31 with the cutting speed “0” does not touch the processing surface 27. Cutting traces are not formed on the processed surface 27 of the susceptor substrate 11.

  The rotary blade 15 cuts a susceptor base material made of a graphite material spirally around the central axis 33 of the portion on which the wafer is placed. As a result, the machining surface 27 of the concave portion 25 that is a circular surface can be continuously cut while the rotary blade 15 is in contact. For this reason, the stepped portion of the cutting trace or the like due to the rotary blade 15 being separated from the surface of the processed surface of the susceptor base material and coming into contact again does not occur on the processed surface 27.

  Further, the rotary blade 15 is preferably cut in a spiral shape from the center of the portion on which the wafer of the susceptor substrate is placed toward the outer periphery. Since the susceptor base material is cut in a spiral shape from the center toward the outer periphery, a small remaining projection is not formed during the cutting process or after the cutting process is completed, and the processing surface 27 is chipped or unavoidable. Can be processed.

FIG. 3 is a schematic diagram of a method for processing a susceptor base material according to the present invention, wherein (a) a plan view showing the relationship between the rotation direction of the rotary blade and the moving direction of the processing surface of the susceptor base material; ) Is a side view thereof. 4A and 4B are schematic views of a method for processing a susceptor base material according to the present invention. FIG. 4A is a cross-sectional view taken along the line P-P in FIG. 3A, and FIG. It is a figure explaining an up cut process in PP cross section of (a).
In FIG. 3, the relationship between the rotation direction of the rotary cutter 15 and the feed direction of the machining surface 27 of the susceptor base material 11 is that the rotation direction of the rotary cutter 15 is the arrow A direction and the feed of the machining surface 27 of the susceptor base material 11 When the direction is the direction of the arrow L, as shown in FIG. 4, so-called downcut machining in which the rotary blade 15 cuts the machining surface 27 with respect to the traveling direction C of the rotary cutter 15, or the rotary cutter 15 Is a so-called down cut that acts to scrape the processed surface 27. That is, the downcut processing can be performed by rotating the blade edge from the surface of the workpiece as shown in FIG. In addition, the upcut process can be performed by rotating the blade edge from the inside of the workpiece as shown in FIG. 4B toward the surface.

  Up-cut processing gives a stable feed stress to the cutting edge and can be safely processed, but an upward tensile force is applied to the processing surface, and the cutting edge may entrap chips and scratch the processing surface 27, and graphite. Generally, it is not suitable for finishing by a brittle material such as a material. On the other hand, in the down cut processing, a downward compressive force is applied to the processed surface. Brittle materials such as graphite materials have a strong compressive strength compared to tensile strength. For this reason, a large force is required for the machined surface compared to the up-cut process, but if the depth of cut is reduced, the chips become smaller, the machined surface is smooth, and there is no chipping or scratching. A smooth surface and is suitable for finishing a brittle material such as a graphite material.

  The movement of the susceptor base material 11 is a rotation around the center of the susceptor base material 11. Thereby, it can cut continuously, with the rotary blade 15 being contacted. Even when there are a plurality of wafer placement surfaces on the susceptor base material 11, the rotary cutter 15 is processed by following the wafer placement surface in the XYZ directions, thereby continuously supporting the susceptor base material 11. Cutting can be performed. The angle at which the rotary blade 15 performs the cutting process by inclining with respect to the normal line 23 of the upper surface 21 of the susceptor substrate 11 is preferably 20 to 70 degrees. If the angle of inclination of the rotary cutter 15 with respect to the normal line 23 of the upper surface 21 of the susceptor base 11 exceeds 70 degrees, the susceptor base and the processing machine are likely to interfere with each other, and the rotary cutter 15 is perpendicular to the rotational axis of the rotary cutter. Since a large radial load component becomes large, the rotary blade is bent and machining accuracy cannot be obtained. When the angle of inclination of the rotary blade 15 with respect to the normal line 23 of the upper surface 21 of the susceptor substrate 11 is less than 20 degrees, glossy cutting traces are easily formed.

  In the processing method of the susceptor base material 11, a portion (wafer placement surface) on which a plurality of wafers are placed may be formed on the susceptor base material 11. As the susceptor base material 11 on which a portion on which a plurality of wafers are placed is formed, for example, a portion on which three wafers are placed can be provided as shown in FIG. By having the concave portions 25 on which a plurality of wafers are placed, each concave portion 25 can be sequentially cut while rotating one susceptor substrate 11.

The shape of the recess 25 in which the susceptor base material 11 is cut is a shape in which the bottom surface of the recess 25 has a curved surface 17. When the wafer is placed and the film forming process is performed by having the curved surface 17, for example, the susceptor and the wafer are less likely to be in point contact, and heat is easily transferred from the susceptor to the wafer evenly. The so-formed wafer can be soaked to make it difficult to be thermally deformed.
An example of the wafer deposition process is epitaxial growth of a compound semiconductor.

  Moreover, it is preferable that the shape of the recessed part 25 by which the cutting process of the susceptor base material 11 was performed is a shape in which the bottom face of the recessed part 25 has the convex curved surface 17. FIG. When a film of a compound semiconductor wafer whose top surface is deformed in a convex direction is placed by forming a convex curved surface 17 on the bottom surface, the distance between the wafer and the susceptor is increased even if the wafer is thermally deformed. Since it can be made small, a susceptor that can transfer heat uniformly from the susceptor to the wafer can be obtained.

  Moreover, it is preferable that the shape of the recess 25 in which the susceptor base material 11 has been cut is similar to the warpage of the wafer that occurs when the wafer is placed and the wafer is deposited. Since the warped shape of the wafer is similar to the shape of the bottom of the concave portion of the susceptor base material 11, even if the wafer is subjected to deformation such as warpage due to the wafer film forming process, the deformed wafer is removed from the bottom surface of the concave portion 25 of the susceptor base material 11. This is because it can be surely supported.

Next, the processing method which processes the susceptor base material 11 using the 5-axis processing machine 39 is demonstrated.
5A and 5B are schematic views of a method for processing a susceptor base material according to the present invention. FIG. 5A is a side view showing an example of a 5-axis processing machine 39, and FIG. 5B is a front view of FIG.
The 5-axis processing machine 39 enables contour control processing of the wafer mounting surface that is a convex curved surface. In the 5-axis machine 39, a column (not shown) is fixed to the bed 41, and the column includes a main shaft 45 that rotates the rotary blade 15 at high speed. The axis of the main shaft 45 coincides with the axis center of the rotary blade 15. The main shaft 45 is supported so as to be movable in the X and Y directions in a plane orthogonal to the axis center of the rotary blade 15. The main shaft 45 is supported so as to be movable in the Z direction which is the vertical direction with respect to the column.

  Below the main shaft 45, there is provided a rotary table 47 for fixing a graphite base material as a workpiece. The rotary table 47 is supported by a rotation mechanism unit 49 fixed to the bed 41 so as to be rotatable in a rotation direction about the central axis 43. The rotation mechanism 49 supports the rotary table 47 so as to be swingable about a swing shaft 51 in a direction orthogonal to the axis center of the rotary blade 15. That is, the 5-axis processing machine 39 has three linear axes and two rotational axes. The five-axis processing machine 39 is an example, and is limited to this as long as the susceptor base material made of graphite having a plurality of wafer placement surfaces can be cut by being inclined using the rotary blade 15. It is not a thing. For example, cutting can be similarly performed with a 5-axis processing machine that swings the rotary blade side instead of the rotary table side.

Next, the effect | action of the processing method of the susceptor base material 11 is demonstrated.
In the processing method of the susceptor base material 11, the rotating shaft 29 of the rotary blade 15 and the normal line 23 of the susceptor base material 11 are inclined and cut. Since the cutting is performed while being inclined, the non-cutting point 31 at the cutting speed “0” of the rotary blade 15 does not contribute to the processing, and the processing surface 27 has substantially the same processing conditions. Note that the non-cutting point 31 having the cutting speed “0” does not have a processing capability and only moves while rubbing the processed surface 27, so that a glossy cutting trace is easily formed. In the case of machining with the rotary blade 15 inclined as in the present embodiment, non-cutting points without machining ability do not contribute to machining, so there is no cutting trace on the surface of the bottom surface of the concave portion of the susceptor substrate. A processed surface 27 is obtained.

  Moreover, it is preferable to make the rotation direction of the rotary blade 15 into a down cut process. As a result, the cutting edge is rotated from the surface of the susceptor substrate toward the inside, so that a cutting mark or a scratch is hardly generated, and the cutting surface can be obtained as a clean finished surface.

  Therefore, according to the processing method of the susceptor base material 11 according to the present embodiment, it is possible to obtain the susceptor base material 11 that does not have a cutting mark or a scratch on the part on which the wafer is placed.

  According to the susceptor base material obtained by the processing method of the susceptor base material 11, since there is no cutting trace on the processing surface 27, the difference in thermal emissivity due to the difference in the surface state due to the cutting trace can be suppressed, and the emissivity can be reduced. Temperature unevenness due to the difference does not occur in the wafer placed on the susceptor base material. As a result, when used as a susceptor for epitaxial growth, it is possible to manufacture a high-quality wafer with no variation in characteristics of a semiconductor product to be cut out.

Next, the Example and comparative example which cut the susceptor base material using the rotary blade are described.
A sample (susceptor base material made of graphite) is fixed on the stage, and surface measurement is performed with a length of 25 mm from the center of the processed portion of the susceptor base material toward the outer peripheral portion. The sample is a susceptor base material with a diameter of 100 mm, and three wafer pockets with a diameter of 50 mm are formed on the processed surface of the susceptor base material. For the surface measuring device, a surface roughness meter of P-15 (stylus type) manufactured by KLA-Tencor is used. The surface measurement conditions are a measurement length of 25 mm, a scanning speed of 100 μm / sec, and a load of 5 mg.
[Example 1]
Using a 5-axis processing machine in which the cutting blade moves in the XYZ directions and the rotary table can swing, the susceptor base material is set on the rotary table to process the wafer pocket.
A ball end mill having a radius of 1 mm is used as the processing tool, and the rotating blade is made to follow so that the inclination angle is inclined by 40 degrees with respect to the normal line of the upper surface of the susceptor substrate, and the rotation speed is set to 18000 rpm. The feeding speed of the susceptor base material is 2100 mm / min.
Since the rotary blade was inclined by 40 degrees, non-cutting points with a processing speed of “0” did not touch the processing surface, and no cutting marks were generated on the processing surface of the susceptor substrate.

[Comparative Example 1]
Using a triaxial processing machine in which the cutting tool can move in the XYZ directions, a susceptor base material was set on a rotary table to process a wafer pocket.
A flat end mill having a radius of 5 mm is used as the processing tool, and the rotary blade has a rotation axis perpendicular to the processing surface and a rotation speed of 18000 rpm. The feeding speed of the susceptor base material is 2100 mm / min.
Since the rotary cutter is not inclined, the non-cutting point at the machining speed “0” touches the machining surface and the rotary cutter moves continuously, so that the surface roughness described later is equivalent to that of the first embodiment. Nevertheless, the occurrence of shiny cutting marks was confirmed.
[Comparative Example 2]
The rotary cutter uses a single blade with a large radius of curvature of 33000 mm and radius of 25 mm so that the blade surface has a curved shape corresponding to the work surface, the rotary cutter is perpendicular to the machining surface, and the rotational speed is set to 5000 rpm. Rotate in position.
Since the rotary cutter is not fed using a large-diameter cutter as the rotary cutter, the non-cutting points are only formed in a very small region at the center of the wafer pocket, and no cutting traces are generated.
The processing conditions (tool, tilt angle, rotation speed, feed rate) of Example 1 and Comparative Examples 1 and 2 are collectively shown in Table 1, and together, the processing surface of the susceptor substrate (the bottom surface of the recess) The presence or absence of cutting marks on the surface) was indicated.

From Table 1 above, in Example 1, although the end mill is cut using the same end mill as in Comparative Example 1, generation of cutting marks is not observed as in Comparative Example 2 using a large-diameter cutter. .
In Example 1, Comparative Example 1, and Comparative Example 2, the surface roughness of the processed susceptor surface was measured. There is no significant difference in any of the measurement results of arithmetic average roughness and ten-point average roughness of Example 1 and Comparative Examples 1 and 2 shown in Table 2. However, the presence of cutting marks can be confirmed in Comparative Example 1. That is, it can be seen that the generation of cutting traces cannot be suppressed by controlling the surface roughness, and the generation of cutting traces can be suppressed by processing without using non-cutting points of the cutting tool. . That is, it is considered that the occurrence of cutting traces can be surely suppressed by using the method for processing a susceptor base material of the present invention that is processed without using non-cutting points.

  In the table, n1 to n3 indicate the measurement results of the surface roughness at the three wafer placement portions of one susceptor.

11 Susceptor substrate 13 Shaft tip 15 Rotating blade 17 Curved surface 21 Upper surface 23 Normal 25 Recessed portion 27 Processing surface 33 Center axis of the portion on which the wafer is placed

Claims (11)

A method of processing a susceptor base material that performs cutting using a rotary blade,
The shaft end of the rotary cutter has an R shape, and the susceptor base material is cut by inclining the rotary cutter at a predetermined angle with respect to the normal line of the upper surface of the susceptor base material. A processing method for a susceptor base material, characterized in that a processed surface having no cutting trace is formed in a recessed portion where the step is performed.   2. The susceptor according to claim 1, wherein the susceptor base material has the concave portion on which a wafer is placed, and the rotary blade cuts a graphite material spirally around a central axis of the concave portion. Substrate processing method.   The susceptor base material processing method according to claim 2, wherein the rotary blade is cut from the center of the concave portion of the susceptor base material toward the outer periphery.   The susceptor substrate processing method according to claim 3, wherein the cutting process is a downcut process.   The susceptor base material processing method according to claim 4, wherein the movement of the susceptor base material is rotation about the center of the susceptor base material.   The susceptor substrate processing method according to any one of claims 1 to 5, wherein an angle of the rotary blade with respect to a normal line of the upper surface of the susceptor substrate is 20 to 70 degrees.   The method for processing a susceptor substrate according to any one of claims 1 to 6, wherein the recess has a shape in which a bottom surface of the recess has a curved surface.   The method of processing a susceptor base material according to claim 7, wherein the shape of the concave portion is a curved surface having a convex bottom surface.   8. The method of processing a susceptor substrate according to claim 7, wherein the bottom surface of the concave portion has a shape similar to a warp that occurs when the wafer is processed.   The susceptor substrate processing method according to claim 2, wherein a plurality of recesses are formed corresponding to the plurality of wafers.   The susceptor base material formed by the processing method of a susceptor base material of any one of Claims 1 thru | or 10.

Images