JP6233209B2 - Susceptor and manufacturing method thereof - Google Patents

Description

  The technical field of the present specification relates to a susceptor and a manufacturing method thereof. More specifically, the present invention relates to a susceptor heated by induction heating and a method for manufacturing the susceptor.

  In vapor phase growth methods such as metal organic chemical vapor deposition (MOCVD) and hydride vapor phase growth (HVPE), a semiconductor layer is deposited on a growth substrate held by a susceptor inside a chamber. In stacking the semiconductor layers, the growth substrate is heated and a source gas is guided to the growth substrate.

  In general, a vapor deposition apparatus using these vapor deposition methods heats a susceptor. The heated susceptor heats the growth substrate. The susceptor heating method includes, for example, an induction heating method in which the susceptor is heated by induction heating, and a heat transfer method in which the susceptor is heated by contacting a heat source.

  In order to grow the semiconductor layer, it is important to uniformly heat the plate surface of the growth substrate. This is because the temperature unevenness of the growth substrate leads to the unevenness of the semiconductor layer. For example, in the case of manufacturing a group III nitride semiconductor light emitting device, the indium concentration is higher at a location where the temperature of the growth substrate is lower than at other locations. In the group III nitride semiconductor light emitting device taken from this low temperature portion, the emission wavelength is shifted. As described above, the temperature unevenness of the growth substrate causes a decrease in the yield of the semiconductor element.

  For this reason, measures have been taken to eliminate temperature unevenness of the growth substrate. For example, Patent Document 1 discloses a technique for easily heating a growth substrate even when an anisotropic warp occurs in the growth substrate when a susceptor heated by induction heating is used ( (See paragraph [0014] of Patent Document 1).

JP 2010-80614 A

  By the way, in induction heating, the heating object is directly heated by generating an eddy current on the surface of the heating object. And depending on the thickness of the heating object, the eddy current generated on the first surface side and the eddy current generated on the second surface side cancel each other. Therefore, the amount of eddy current cancellation varies depending on the thickness of the susceptor. That is, the magnitude of the eddy current varies depending on the thickness of the susceptor. This changes the temperature distribution of the susceptor. The temperature distribution of the susceptor naturally affects the temperature distribution of the growth substrate. The temperature distribution of the growth substrate affects the crystallinity of the semiconductor layer grown on the growth substrate. Therefore, in the induction heating type susceptor, it is necessary to suitably design the thickness of the susceptor.

  In addition, a plate-like carbon material coated with SiC is often used as an induction heating type susceptor. In the step of forming the plate-like carbon material, a material such as a binder is mixed into the carbon material. Therefore, the electrical resistivity of the completed carbon material varies due to the concentration and distribution of the binder and the like, and the temperature and humidity during production. For this reason, even if the thickness of the susceptor is designed based on a carbon material having a predetermined electrical resistivity, variation depending on these manufacturing conditions occurs. That is, when susceptors of different lots are used, semiconductors are stacked under different temperature distribution conditions.

  The technique of this specification has been made to solve the problems of the conventional techniques described above. That is, the problem is to provide a susceptor that reduces variations in temperature distribution in the susceptor heated by induction heating and a method for manufacturing the susceptor.

The susceptor manufacturing method in the first aspect is a susceptor manufacturing method heated by induction heating. In this manufacturing method, an electric resistivity measuring step for measuring the electric resistivity of the carbon material, and a carbon base material is manufactured by processing the carbon material based on the electric resistivity of the carbon material measured by the electric resistivity measuring step. A carbon substrate processing step. In the carbon base material processing step, a carbon base material having a central portion having a first thickness A1 and an outer peripheral portion having a second thickness B1 thicker than the first thickness A1 is produced. In this processing, the higher the electrical resistivity of the carbon base material measured in the electrical resistivity measurement step, the thicker the first thickness A1 of the central portion of the carbon base material is processed. Further, the first thickness A1 and the second thickness B1 are expressed by the following equations.
0.9 ・ k ・ ρ ^1/2 ≦ A1 / B1 ≦ 1.1 ・ k ・ ρ ^1/2
δ <A1 <2.δ
2 · δ <B1
ρ: Electric resistivity of carbon substrate of susceptor
k: Constant (0.10 (μΩ · m) ^−1/2 or more and 0.15 (μΩ · m) ^−1/2 or less)
δ: Penetration depth of eddy current
The carbon material is processed to satisfy

  In the susceptor manufactured by this manufacturing method, the carbon substrate is heated by induction heating. Further, when comparing a plurality of susceptors manufactured by this manufacturing method, the higher the electrical resistivity of the carbon base material, the thicker the first thickness A1 of the central portion of the carbon base material. Conversely, the thicker the first thickness A1 of the central portion of the carbon substrate, the higher the electrical resistivity of the carbon substrate. In this manufacturing method, when manufacturing a carbon material, a binder or the like is mixed with the carbon-based raw material. At that time, variations in the specific electrical resistivity of the carbon material occur due to variations in the concentration of the binder, variations in the particle size of the carbon-based raw material, and the like. In this susceptor manufacturing method, variations in temperature distribution are suppressed by adjusting the thickness of the susceptor according to the electrical resistivity.

The first thickness A1, along with a wall thickness for the desired temperature distribution, a thickness greater than the current penetration depth due to the skin effect of the induction heating. The second thickness B1 is a constant thickness that is not affected by the current penetration depth due to the skin effect of induction heating. That is, the second thickness B1 is a thickness at which the effect of canceling eddy current is sufficiently small.

The manufacturing method of the susceptor in a 2nd aspect has a coating process which coats a carbon substrate with SiC after a carbon substrate processing process.

The plurality of susceptors in the third aspect have a carbon substrate heated by induction heating. The carbon substrate has a central portion having a first thickness A1 and an outer peripheral portion having a second thickness B1 that is thicker than the first thickness A1. And the 1st thickness A1 of the center part of a carbon base material is so thick that the electrical resistivity of a carbon base material is high among several susceptors . Further, the first thickness A1 and the second thickness B1 are given by
0.9 ・ k ・ ρ ^1/2 ≦ A1 / B1 ≦ 1.1 ・ k ・ ρ ^1/2
δ <A1 <2.δ
2 · δ <B1
ρ: Electric resistivity of carbon substrate of susceptor
k: Constant (0.10 (μΩ · m) ^−1/2 or more and 0.15 (μΩ · m) ^−1/2 or less)
δ: Penetration depth of eddy current
Meet.

  In the present specification, a susceptor that reduces variations in temperature distribution in a susceptor heated by induction heating and a method for manufacturing the susceptor are provided.

It is a figure which shows schematic structure of the vapor phase growth apparatus in embodiment. It is a top view which shows the susceptor in embodiment. It is sectional drawing which shows the III-III cross section of FIG. It is a bottom view which shows the carbon base material of the susceptor in embodiment. It is a conceptual diagram which shows the mode of the eddy current inside the susceptor in embodiment. It is a figure for demonstrating the manufacturing method of the susceptor in embodiment.

  Hereinafter, specific embodiments will be described with reference to the drawings, taking as an example a susceptor heated by induction heating and a method of manufacturing the susceptor. However, it is not limited to these embodiments.

1. Vapor Phase Growth Apparatus FIG. 1 is a diagram showing a schematic configuration of a vapor phase growth apparatus 1 having a susceptor 100 of the present embodiment. The vapor deposition apparatus 1 is for growing a semiconductor layer by metal organic chemical vapor deposition (MOCVD). More specifically, the vapor phase growth apparatus 1 deposits a group III nitride semiconductor on the growth substrate held by the susceptor 100. The vapor phase growth apparatus 1 heats the susceptor 100 by high frequency induction heating.

  The vapor phase growth apparatus 1 includes a chamber 10, a susceptor 100, a susceptor mounting portion 20, a rotating shaft 30, a motor 40, a gas inlet 50, a gas outlet 60, an rf coil 70, and a high frequency power source 80. And a gas supply unit 90 and a mass flow controller 91.

  The chamber 10 is a furnace body for depositing semiconductor crystals by supplying a source gas onto the growth substrate. The susceptor 100 is for holding a growth substrate. The susceptor mounting portion 20 is for mounting the susceptor 100 to the rotating shaft 30. The rotary shaft 30 is for transmitting the rotational drive of the motor 40 to the susceptor 100. The motor 40 is for rotating the susceptor 100. For this reason, the susceptor 100 can be rotated with respect to the chamber 10 while the semiconductor layer is grown.

  The gas supply unit 90 is for supplying various source gases. In FIG. 1, the gas supply unit 90 is illustrated in a simplified manner, but actually supplies a plurality of gases. The mass flow controller 91 is for controlling the flow rates of various gases supplied to the gas inlet 50. The gas inlet 50 is for introducing a source gas into the chamber 10. The gas exhaust port 60 is for exhausting gas from the inside of the chamber 10.

  The high frequency power supply 80 is for flowing a high frequency current through the rf coil 70. The rf coil 70 is disposed so as to cover the chamber 10. Therefore, the susceptor 100 is located inside the rf coil 70. The rf coil 70 is for generating an alternating magnetic field. The magnetic field generated by the rf coil 70 is formed parallel to the plate surface of the growth substrate held by the susceptor 100. This magnetic field is formed, for example, in parallel to a line connecting the gas inlet 50 and the gas outlet 60.

2. Susceptor 2-1. Material of Susceptor FIG. 2 is a plan view showing the susceptor 100 of the vapor phase growth apparatus 1 of the present embodiment. The susceptor 100 is for holding the growth substrate at least during the deposition of the semiconductor layer on the growth substrate. The susceptor 100 is a carbon base material coated with SiC. This carbon substrate is heated by a high frequency magnetic field formed by the rf coil 70. The susceptor 100 is heated by such an induction heating method.

2-2. 2. Shape of susceptor As shown in FIG. 2, the susceptor 100 has a disc shape as a whole. The susceptor 100 has five substrate platforms 130. The substrate placement unit 130 is for placing a growth substrate. In FIG. 2, a boundary line between a central part 110 and an outer peripheral part 120 described later is virtually drawn with a broken line.

  3 is a cross-sectional view showing a cross section taken along line III-III in FIG. As shown in FIG. 3, the susceptor 100 has a carbon base material BM1 and a coating part S1. The carbon base material BM1 is made of a carbon material. The coating part S1 is made of SiC. As described above, the carbon base material BM1 is heated by induction heating. The carbon base material BM1 has a central portion 110 and an outer peripheral portion 120. The central part 110 has a first thickness A1. The outer peripheral portion 120 has a second thickness B1. As shown in FIG. 3, the second thickness B <b> 1 of the outer peripheral portion 120 is thicker than the first thickness A <b> 1 of the central portion 110.

  FIG. 4 is a bottom view of the carbon base material BM1. As shown in FIG. 4, the outer peripheral part 120 is a ring-shaped part along the outer edge of the carbon base material BM1. The center part 110 is a disk-shaped part near the center of the carbon base material BM1. Note that, in FIG. 4, portions that are attached to the susceptor attachment portion 20 are omitted. Thus, the shape of the carbon base material BM1 is a disc shape as a whole, and includes the central portion 110 and the outer peripheral portion 120 having a thickness greater than that of the central portion 110.

3. 3. Thickness of susceptor and penetration depth of eddy current 3-1. Eddy current On the surface of the carbon substrate BM1 of the susceptor 100, an eddy current is generated by a high-frequency magnetic field formed by the rf coil 70. Due to this eddy current, the carbon base material BM1 is heated.

  FIG. 5 is a diagram for comparing the state of eddy current between the central portion 110 and the outer peripheral portion 120 of the carbon base material BM1 of the susceptor 100. FIG. As shown in FIG. 5, eddy currents flow on both surfaces of the carbon base material BM1.

  As shown in FIG. 5, the central portion 110 can virtually assume areas DA1, DA2, and DA3. The region DA1 is on the surface (first surface) side on which the growth substrate is placed. The area DA2 is located on the surface (second surface) opposite to the area DA1. The area DA3 is located between the area DA1 and the area DA2. Eddy currents are generated in the areas DA1 and DA2 of the central portion 110. In the area DA3 of the central portion 110, eddy currents cancel each other. FIG. 5 conceptually illustrates this state. However, in practice, the three areas DA1, DA2, and DA3 cannot be distinguished so clearly.

  On the other hand, the outer periphery 120 can virtually assume the regions DB1, DB2, and DB3. The region DB1 is on the surface (first surface) side on which the growth substrate is placed. The region DB2 is located on the surface (second surface) side opposite to the region DB1. The region DB3 is located between the region DB1 and the region DB2. In the regions DB1 and DB2 of the outer peripheral portion 120, eddy currents are generated. In the region DB3 of the outer peripheral portion 120, eddy currents cancel each other. The areas DB1, DB2, and DB3 are not always clearly distinguishable as are the areas DA1, DA2, and DA3.

  As described above, the eddy currents flow on the surfaces of the first surface and the second surface of the carbon base material BM1, and cancel each other out near the center of the plate thickness. However, the degree of cancellation differs between the central portion 110 and the outer peripheral portion 120. That is, the area DA3 in the central part 110 is larger than the area DB3 in the outer peripheral part 120. The degree of current cancellation at the central portion 110 is greater than the degree of current cancellation at the outer peripheral portion 120. For this reason, the calorific value of the carbon base material BM1 of the susceptor 100 is slightly larger at the outer peripheral portion 120 than at the central portion 110. Therefore, it is possible to effectively heat the outer peripheral portion of the growth substrate that tends to be low in temperature.

3-2. Eddy current penetration depth The degree of eddy current cancellation depends on how deep the eddy current penetrates. The penetration depth δ of the eddy current is given by the following equation.
δ = 503 (ρ / (f · μr)) ^1/2 (1)
δ: penetration depth of eddy current (m)
ρ: Electric resistivity of carbon substrate of susceptor
μr: Relative permeability of susceptor
f: Frequency of high frequency current (Hz)

  Here, the penetration depth δ of eddy current indicates how much eddy current penetrates from the surface of the carbon base material BM1. The penetration depth δ of the eddy current indicates a depth at which the eddy current becomes 1 / e with respect to the eddy current on the outermost surface. Therefore, actually, a small eddy current flows also at a position deeper than the penetration depth δ of the eddy current. The eddy current penetration depth δ is related to the degree of eddy current cancellation, as shown in FIG. And as Formula (1) shows, the penetration depth δ of the eddy current depends on the electrical resistivity ρ of the carbon base material BM1. Here, examples of the frequency f of the high-frequency current include frequencies from 10 kHz to 100 kHz. Alternatively, other frequencies may be used.

  By the way, when manufacturing the susceptor 100, a carbon material is used. As will be described later, this carbon material is manufactured by blending a carbon-based material with a binder and the like and then sintering. Therefore, the electrical resistivity of the carbon material to be manufactured varies to some extent depending on the blending ratio of the binder, the generation conditions, the temperature and humidity environment, and the like. As shown in Expression (1), when the electric resistivity of the carbon material varies, the eddy current penetration depth δ of the carbon material also varies. That is, the temperature distribution of the susceptor 100 may deviate from the temperature distribution assumed when the susceptor 100 was designed.

  Therefore, as described below, the first thickness A1 of the central portion 110 of the carbon base material BM1 is adjusted according to the electrical resistivity of the carbon material.

3-3. Relational expression of susceptor thickness The susceptor 100 of the present embodiment is processed so that the first thickness A1 of the central portion 110 and the second thickness B1 of the outer peripheral portion 120 satisfy the following expressions.
0.9 · k · ρ ^1/2 ≤ A1 / B1 ≤ 1.1 · k · ρ ^1/2 (2)
A1: First thickness
B1: Second thickness
ρ: Electric resistivity of carbon substrate of susceptor
k: constant

Here, the constant k is, for example, in the range of 0.10 (μΩ · m) ^{−1/2 to} 0.15 (μΩ · m) ^−1/2 . The constant k will be described later. As in equation (2), the first thickness A1 is changed according to the electrical resistivity ρ. Thereby, the influence of the dispersion | variation in the electrical resistivity of a carbon material can be suppressed.

Further, the first thickness A1 and the second thickness B1 are expressed by the following equation: δ <A1 <2.δ (3)
2 · δ <B1
δ: Satisfies eddy current penetration depth. In the formula (3), the first thickness A1 is a thickness for obtaining a desired temperature distribution. The first thickness A1 is greater than the eddy current penetration depth δ due to the skin effect of induction heating. The second thickness B1 is a constant thickness that is not affected by the eddy current penetration depth δ due to the skin effect of induction heating. That is, the second thickness B1 is a thickness at which the effect of canceling eddy current is sufficiently small.

4). Electrical resistivity of susceptor When manufacturing the susceptor 100, a carbon material is manufactured by blending a carbon-based material with a binder and the like and sintering it as described later. Depending on the blending ratio of the binder, the generation conditions, the temperature and humidity environment, etc., the electrical resistivity inherent to the carbon substrate to be produced varies to some extent. When the electric resistivity of the carbon material varies, the performance of the susceptor 100 after manufacturing also varies.

  As shown in Expression (2), the penetration depth δ of eddy current is proportional to the square root of the electrical resistivity ρ of the carbon base material BM1. Therefore, for example, if the electrical resistivity of the manufactured carbon base material BM1 is smaller than the reference value, the penetration depth δ of the eddy current of the carbon base material also takes a small value accordingly. When the penetration depth δ of the eddy current is changed, the degree of heating at the central portion 110 of the susceptor 100 and the outer peripheral portion 120 of the susceptor 100 is different from that at the time of design. As a result, the temperature distribution varies.

  If the temperature distribution of the susceptor 100 is different from the design time, the temperature distribution of the growth substrate supported by the susceptor 100 also varies. As a result, the composition of the semiconductor layer to be grown varies near the center and the outer periphery of the growth substrate. As a result, the yield of the semiconductor element is reduced.

  Therefore, as shown in Formula (2), the first thickness A1 of the central portion 110 of the susceptor 100 and the second thickness B1 of the outer peripheral portion 120 are set. Then, as will be described later, the first thickness A1 of the central portion 110 is changed according to the measured value of the electrical resistivity of the carbon substrate.

Table 1 is a table illustrating the electrical resistivity ρ and the like. The first column in Table 1 is the electrical resistivity ρ (μΩ · m) of the carbon base material BM1. The second column in Table 1 is the ratio T1 between the first thickness A1 of the central portion 110 and the second thickness B1 of the outer peripheral portion 120. The third column in Table 1 is a ratio T2 obtained by dividing the ratio T1 of the second column by the square root of the electrical resistivity ρ. The fourth column of Table 1 is a value obtained by dividing the ratio T2 of the third column by the constant k in Equation (2). In Table 1, the constant k is set to 0.1254 (μΩ · m) ^−1/2 . The second thickness B1 is a constant thickness. On the other hand, the first thickness A1 is changed.

  As shown in Table 1, the higher the electrical resistivity of the carbon base material BM1, the thicker the first thickness A1 of the central portion 110 of the carbon base material BM1. Therefore, even if the electrical resistivity of the carbon material varies, the temperature distribution of the susceptor 100 hardly varies between lots. This is because the variation in the electrical resistivity of the carbon material is absorbed by adjusting the first thickness A1 of the central portion 110.

Here, T3 in the fourth column of Table 1 is a value obtained by dividing Equation (2) by k · ρ ^1/2 . In Table 1, T3 (= A1 / (B1 · k · ρ ^1/2 )) in the fourth column is 0.95 or more and 1.05 or less. Therefore, when the constant k is 0.1254 (μΩ · m) ^−1/2 , of course, the expression (2) is satisfied.

The constant k may be selected as appropriate. If the constant k is selected within the range of 0.10 (μΩ · m) ^{−1/2 to} 0.15 (μΩ · m) ^−1/2 , Equation (2) may be satisfied. Preferably, it is in the range of 0.11 (μΩ · m) ^−1/2 or more and 0.14 (μΩ · m) ^−1/2 or less. More preferably, it is in the range of 0.12 (μΩ · m) ^−1/2 or more and 0.13 (μΩ · m) ^−1/2 or less.

5. Thus, in the present embodiment, the susceptor 100 is processed according to the electrical resistivity of the carbon material that is the material of the susceptor 100. Therefore, even when the semiconductor layer is grown using susceptors 100 of different lots, the temperature distribution of the susceptor 100 is hardly different from the targeted temperature distribution. Therefore, variations in the semiconductor layer are unlikely to occur.

  Here, it is assumed that the susceptor 100 is manufactured from three carbon materials C1, C2, and C3. And it is assumed that it was the carbon material C1, the carbon material C2, and the carbon material C3 in order from a thing with low electrical resistivity. In that case, the first thickness A1 of the central portion 110 of the susceptor 100 manufactured from the carbon materials C1, C2, and C3 is different.

  Of the susceptors 100 manufactured from the carbon materials C1, C2, and C3, the first thickness A1 of the central portion 110 of the susceptor 100 manufactured from the carbon material C1 is the thinnest. That is, the first thickness A1 of the central portion 110 of the susceptor 100 manufactured from the carbon material C1 is thinner than the first thickness A1 of the central portion 110 of the susceptor 100 manufactured from the other carbon materials C2 and C3. The next thinnest is the first thickness A1 of the central portion 110 of the susceptor 100 manufactured from the carbon material C2. And 1st thickness A1 of the center part 110 of the susceptor 100 manufactured from the carbon material C3 is the thickest. Thus, the higher the electrical resistivity of the carbon substrate, the thicker the first thickness A1 of the central portion 110 of the susceptor 100 is.

  When there are a large number of susceptors 100, the electrical resistivity of each susceptor 100 and the first thickness A1 of the central portion 110 of each susceptor 100 have a correlation. That is, the higher the electrical resistivity of the carbon material, the thicker the first thickness A1 of the central portion 110 of the susceptor 100 is.

6). Manufacturing method of susceptor 6-1. Carbon material production process Binder is mixed into carbon-based material. Then, the carbon-based material is formed into a rectangular parallelepiped shape and sintered. And this sintered compact is cut out. Thereby, as shown in FIG. 6, the plate-shaped carbon material 200 is produced.

6-2. Electrical resistivity measurement step The plate-like carbon material 200 has a thickness B1. And the electrical resistivity of the carbon material 200 is measured. In measuring this electrical resistivity, JIS R 7222: 1997 (method for measuring physical properties of graphite material) is used.

6-3. Next, based on the measured electrical resistivity of the plate-like carbon material 200, the plate-like carbon material 200 is processed into a disk shape. And carbon base material BM1 which has the center part 110 of 1st thickness A1, and the outer peripheral part 120 of 2nd thickness B1 is produced. Here, the higher the electrical resistivity of the carbon material 200, the thicker the first thickness A1 of the central portion 110 of the carbon base material BM1 is processed. The lower the electrical resistivity of the carbon material 200, the thinner the first thickness A1 of the central portion 110 of the carbon base material BM1 is processed. That is, the plate-like carbon material 200 is shaved so as to satisfy the formula (2). In addition to the formula (2), it is more preferable to satisfy the formula (3).

  In addition, the groove | channel for fitting in the location fixed to the susceptor attachment part 20, for example, the susceptor attachment part 20, is formed. Of course, other connection structures may be provided. Thereby, carbon base material BM1 is manufactured.

6-4. Coating Step Next, the carbon base material BM1 is coated with SiC using a plasma CVD method or the like. Thus, the susceptor 100 is manufactured.

7). Modification 7-1. Semiconductor Device In this embodiment, the vapor phase growth apparatus 1 is used to manufacture a group III nitride semiconductor light emitting device. However, it can of course be used to manufacture other semiconductor elements. For example, a light-emitting element having a semiconductor layer other than a group III nitride system. Further, it may be a semiconductor element such as HEMT.

7-2. Number of Substrate Placement Units In the present embodiment, as shown in FIG. 2, the susceptor 100 has five substrate placement units 150. However, for example, a susceptor having a single substrate platform 150 may be used. Further, a susceptor having six substrate placement units 150 may be used. In this way, the number of substrate placement units 150 may be any number.

7-3. Vapor Phase Growth Method In this embodiment, the vapor phase growth apparatus 1 is configured to deposit a semiconductor layer on a growth substrate by MOCVD. However, other vapor phase growth methods such as the HVPE method may be used.

7-4. Combination Moreover, you may combine each of said modification freely.

8). Summary of the present embodiment As described in detail above, in the susceptor 100 of the present embodiment, the eddy current generated on the first surface side and the eddy current generated on the second surface side preferably work together. The thickness A1 of the central part 110 and the thickness B1 of the outer peripheral part 120 were determined. Therefore, the temperature distribution of the susceptor 100 is suitable during semiconductor growth. Therefore, the yield of semiconductor devices manufactured using this susceptor is good.

  Note that this embodiment is merely an example, and does not limit the technique of this specification. Accordingly, the technology of the present specification can be variously improved and modified without departing from the gist thereof. For example, it is not limited to the metal organic chemical vapor deposition method (MOCVD method). Other crystal growth methods such as the HVPE method may be used.

DESCRIPTION OF SYMBOLS 1 ... Vapor growth apparatus 100 ... Susceptor 110 ... Center part 120 ... Outer peripheral part BM1 ... Carbon base material

Claims (3)

In the method of manufacturing a susceptor heated by induction heating,
An electrical resistivity measurement step for measuring electrical resistivity of the carbon material;
A carbon substrate processing step of processing the carbon material based on the electrical resistivity of the carbon material measured by the electrical resistivity measurement step to produce a carbon substrate;
Have
In the carbon substrate processing step,
A central portion having a first thickness A1,
An outer peripheral portion having a second thickness B1 thicker than the first thickness A1,
Producing the carbon substrate having
The higher the electrical resistivity of the carbon substrate measured in the electrical resistivity measurement step, the thicker the first thickness A1 of the central portion of the carbon substrate ,
The first thickness A1 and the second thickness B1 can be expressed by the following formula:
0.9 ・ k ・ ρ ^1/2 ≦ A1 / B1 ≦ 1.1 ・ k ・ ρ ^1/2
δ <A1 <2.δ
2 · δ <B1
ρ: Electric resistivity of carbon substrate of susceptor
k: Constant (0.10 (μΩ · m) ^−1/2 or more and 0.15 (μΩ · m) ^−1/2 or less)
δ: Penetration depth of eddy current
A method of manufacturing a susceptor , wherein the carbon material is processed to satisfy the above . In the manufacturing method of the susceptor of Claim 1 ,
After the carbon substrate processing step,
A method for producing a susceptor comprising a coating step of coating the carbon substrate with SiC. In multiple susceptors,
Having a carbon substrate heated by induction heating,
The carbon substrate is
A central portion having a first thickness A1,
An outer peripheral portion having a second thickness B1 thicker than the first thickness A1,
Have
The higher the plurality of having a high electrical resistivity of the carbon substrate of the susceptor, the rather thick said first thickness A1 of the central portion of the carbon substrate,
The first thickness A1 and the second thickness B1 are given by
0.9 ・ k ・ ρ ^1/2 ≦ A1 / B1 ≦ 1.1 ・ k ・ ρ ^1/2
δ <A1 <2.δ
2 · δ <B1
ρ: Electric resistivity of carbon substrate of susceptor
k: Constant (0.10 (μΩ · m) ^−1/2 or more and 0.15 (μΩ · m) ^−1/2 or less)
δ: Penetration depth of eddy current
A susceptor characterized by satisfying .

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