JPH10223546A - Susceptor for chemical vapor deposition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the sagging phenomenon of an electrical specific difference such as a spread resistance and a non-uniformity in a wafer surface by forming a semiconductor wafer placement recessed part on the upper surface of a projecting part that projects from the surface of a flat plate. SOLUTION: A susceptor 1 for chemical vapor deposition is entirely formed in a circular flat-plate body with a flat surface 2 and a vent hole 3 for gas nozzle when setting a reaction oven such as in bell jar type is formed through the center. A protrusion 4 on the flat surface 2 is arranged and formed at an equal interval nearly along a circumference. Also, a recess 5 of a counter sink part for placing a semiconductor wafer is formed on the upper surface of the protrusion 4. Also, in the susceptor 1, the surface of a base 10 such as a carbon material in this kind of shape is covered with an SiC film 11 with improved corrosion resistance. In the susceptor that is formed this way, the arrangement position of the protrusion 4 for forming the recess 5 on the upper surface is not limited particularly and the protrusion 4 can be arranged properly at a specific position for providing a counter sink part for placing a semiconductor wafer on the flat surface 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a susceptor for vapor phase growth, and more particularly, to a susceptor for mounting a semiconductor wafer formed on an upper surface of a projection protruding from a flat plate surface by a predetermined thickness. Used to form a plurality of single-crystal film layers having different electrical characteristics by chemical vapor deposition on a substrate such as a single-crystal silicon substrate as in the formation of a two-layer structure epitaxial wafer such as an insulated gate bipolar transistor (wafer) wafer. In particular, different electrical characteristics, for example, SR values (Spreading Resist)
The present invention relates to a susceptor for vapor phase growth that can be changed steeply without causing a dripping phenomenon in which a difference in ance (spreading resistance) changes gradually.

[0002]

2. Description of the Related Art An I-type semiconductor device having an epitaxial film having a two-layer structure
A multi-layered wafer in which a plurality of single crystal film layers having different electric characteristics are formed on a single crystal silicon substrate such as a GBT wafer,
It is conventionally known that a film is formed on a substrate such as a single crystal silicon substrate by a chemical vapor deposition method. The difference in electrical characteristics of each single crystal film layer, for example, in an IGBT wafer,
Generally, the first layer formed on the substrate has a higher impurity concentration of the carrier so as to have a lower resistance value, and the second layer formed on the first layer has a lower impurity concentration. It is formed to have higher resistance. in this case,
The SR value in the depth direction near the interface between the first layer and the second layer changes sharply without gradually lowering, that is, the sagging phenomenon occurs in the different electrical characteristics between the respective film layers of the multilayer structure. It is known that a wafer having a layer structure that changes rapidly without occurrence can provide a device having excellent characteristics. On the other hand, it has also been confirmed that device characteristics deteriorate when a so-called sagging phenomenon occurs in which the difference in electrical characteristics such as the SR value gradually changes. Therefore, it is desired that a multi-layered wafer such as an IGBT wafer can be obtained by forming a film such that the electrical characteristics such as the SR value between the layers change sharply as described above.

[0003]

However, the profile obtained by measuring the electrical characteristics in the depth direction, for example, the SR value of a two-layer structure, in a multilayer epitaxial wafer formed by a conventional chemical vapor deposition method. Is generally observed that a sagging phenomenon occurs near the interface between the two layers. It is also observed that such a drooping phenomenon of the SR value in the depth direction becomes larger in the peripheral portion than in the central portion of the wafer. The fact that the degree of sag of the SR value differs between the central portion and the peripheral portion of the wafer means that the in-plane characteristics of the wafer are not uniform but vary, resulting in non-uniform device characteristics. One of the causes of such a droop phenomenon in the change of the SR value is that the high resistance second layer having low impurity concentration is generally formed on the low resistance first layer which is high concentration impurity. It is considered that high-concentration impurities deposited on the susceptor during the formation of the first layer affect the formation of the second layer. Also, the fact that the sagging phenomenon is greater in the peripheral portion than in the central portion of the wafer means that a high concentration of impurities is deposited on the susceptor during the formation of the first layer, and the impurities deposited on the susceptor are removed by the peripheral portion of the wafer during the formation of the second layer. It is thought to have a significant effect.

[0004] In order to prevent the influence of impurities at the time of forming the first layer, for example, after forming the first layer, the susceptor is replaced or transferred to another vapor deposition apparatus to form the second layer. That is being done. In other words, this method is to avoid the influence of impurities deposited on the susceptor by preventing the second layer from being formed after the formation of the first layer using the same susceptor or apparatus. Further, an impurity deposited during the formation of the first layer is removed by etching, and then the second layer is formed. However, the above-mentioned susceptor replacement, cleaning, transfer to another device, etc. are performed by temporarily stopping or switching the vapor phase growth reaction, which complicates the operation in the manufacturing process and lowers productivity. But not preferred. On the other hand, one of the applicants first
Due to the problem of epitaxial phase growth of T wafer,
JP-A-203831 discloses a method of first growing a low-resistance first layer on a substrate, then growing an undoped layer containing no impurity, and continuously growing a high-resistance second layer on the undoped layer. Has proposed a chemical vapor deposition method in which the difference in resistance between the first layer and the second layer is sharp.

The method proposed above has been studied from the viewpoint of process such as inconvenience in operation, and is preferable from the viewpoint of a manufacturing process because vapor phase growth can be continuously performed. on the other hand,
An object of the present invention is to provide an improvement from the viewpoint of an apparatus for preventing inconveniences such as dripping of the SR value change at the boundary surface between the two layers and inhomogeneity thereof. That is, the above-mentioned disadvantages are intended to be solved by improving members of an apparatus for forming an epitaxial wafer having a multilayer structure, such as an IGBT wafer having a two-layer structure, by chemical vapor deposition. For this purpose, the present inventors have studied the above-described deposited impurities on the susceptor, the influence of which has been a problem. As a result, in the susceptor used for epitaxial growth, a predetermined convex portion is provided on a flat plate surface, and a concave portion for mounting and holding a wafer is formed on the upper surface of the convex portion, so that a difference in electrical characteristics such as the SR value is obtained. The present inventors have found that the dripping phenomenon and inhomogeneity in the wafer surface can be eliminated, and the present invention has been completed.

[0006]

According to the present invention, there is provided a susceptor for vapor phase growth comprising a carbon substrate surface coated with a SiC film, wherein one or more projections projecting from the surface of a flat plate are formed. A susceptor for vapor phase growth, wherein the susceptor has a semiconductor wafer mounting concave portion formed on the upper surface of the convex portion. In the susceptor for vapor phase growth of the present invention, it is preferable that the thickness of the projection is 1/7 to 2/7 of the thickness of the flat plate. Further, the radius of the upper surface of the convex portion is 3 to 3 times larger than the radius of the concave portion.
Preferably, it is formed to be 20 mm larger.

According to the present invention, there is provided a susceptor for vapor phase growth having a carbon substrate surface coated with a SiC (silicon carbide) film as described above, wherein a recess for mounting a semiconductor wafer is projected from a flat plate surface. Is formed on the upper surface of the convex portion, and is heated by the heater disposed below the susceptor, so that the temperature of the flat surface becomes higher than that of the upper surface of the convex portion. Therefore, when the first deposition dopant gas is purged with the hydrogen gas during the switching operation to the second layer deposition, the first layer vapor deposition film deposited on the silicon wafer is not affected. Since impurities adhering to the flat surface of the susceptor at the time of the first film formation with a high impurity concentration can be removed by evaporation at a high temperature, the residual impurity concentration on the susceptor surface of the present invention is significantly reduced as compared with the conventional susceptor. Then, in the second layer film forming process after the gas purge with the hydrogen gas, the second layer is formed with a predetermined low concentration dopant from the beginning of the film formation.
Therefore, in the epitaxial wafer having a multilayer structure having different electrical characteristics formed by using the susceptor of the present invention, the gradient of the SR value near the boundary surface of each layer becomes steep, and the sagging phenomenon is suppressed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments with reference to the drawings. However, the present invention is not limited to the following examples. FIG. 1 is a schematic plan view (A) of an embodiment of a susceptor for vapor phase growth according to the present invention, and an end view (B) of a cross section taken along the line BB of FIG. In FIG. 1, a susceptor 1 for vapor phase growth is entirely formed in a circular flat plate having a flat plate surface 2, and a gas nozzle through hole 3 when set in a bell-jar type reaction furnace is formed at the center thereof. It is formed through. Protrusions 4 projecting from the flat plate surface 2 are formed at substantially equal intervals along the circumference. Further, a concave portion 5 of a counterbore portion for mounting a semiconductor wafer is formed on the upper surface of the convex portion 4. This is different from the conventional susceptor in which a counterbore portion is formed in a concave shape on the upper surface of the flat plate surface 2. The susceptor 1 is, like the conventional susceptor for vapor phase growth, coated on the surface of the base material 10 such as a carbon material having the above-mentioned shape with the SiC film 11 having excellent corrosion resistance.

In the susceptor of the present invention formed as described above, the position of the convex portion 4 forming the concave portion 5 on the upper surface thereof is not particularly limited. It can be appropriately arranged at the planned installation position.
Usually, it is disposed at the same position as the counterbore part disposed on the conventional susceptor. By forming the portions having different thicknesses on the flat plate surface in this manner, when the susceptor is heated from the lower heater, the flat plate surface and the upper surface of the convex portion formed on the flat plate surface have:
A relatively high temperature portion and a low temperature portion are formed. Since the susceptor of the present invention mounts the wafer to be subjected to the film processing on the relatively low-temperature portion, the portion on which the wafer is mounted is kept at a relatively low temperature during the gas purging process when switching to the film forming process under different conditions. While holding, the temperature of the flat plate surface can be made relatively high. Therefore, before the next film formation step, the dopant component adhered to the flat plate surface in the previous film formation step can be removed by evaporation at a high temperature, and the influence of the film formation conditions of the preceding or subsequent step in each film formation step is continuous. Each film can be independently formed without receiving the same. In this case, the rising height of the projection from the flat plate surface, that is, the thickness (t) of the projection and the thickness (T) of the flat plate are set to have a relationship of t = 1 / 7T to 2 / 7T. If the thickness of the convex portion is less than 1 / 7T, the temperature difference between the flat plate surface 2 and the upper surface of the convex portion 4 is small, so that the amount of evaporation of impurities attached to the flat plate surface 2 decreases, which is not preferable. On the other hand, 2/7
If the temperature exceeds T, the temperature difference becomes large and cracks may occur in the susceptor, which is not preferable. Generally, the thickness of the flat plate surface is appropriately selected according to the heating power of the heater such as the high-frequency oscillation output of the reaction furnace of the vapor phase growth apparatus to be used. For example, a disk-shaped susceptor having an outer diameter of 640 to 900 mmφ is usually formed to a disk thickness of about 12 to 22 mm.

In the susceptor for vapor phase growth of the present invention,
In FIG. 1, the flat plate surface 2, the convex portions 4, and the concave portions 5 are all shown as circular shapes, but their shapes and sizes are not particularly limited. It can be appropriately selected according to the use conditions of the reaction furnace and the like. Usually, the flat surface has the same size and shape as the conventional one. Also, the shape and size of the convex portion are
It suffices if the semiconductor wafer mounting recess can be formed on the upper surface.
Usually, since the concave portion is formed in a circular shape in accordance with the circular shape of the wafer to be mounted, it is preferable that the convex portion is also formed to have a circular upper surface. In this case, if the upper surface is a circle having a thickness capable of forming the concave portion, the rising of the convex portion from the susceptor surface is not particularly limited. Usually, it is formed vertically, but may have a frustum-shaped taper. Usually, the convex portion is formed in a cylindrical shape on the susceptor surface. A flat plate surface can be formed by grinding using a thick flat plate while leaving a convex portion in a columnar shape, which is convenient in manufacturing. The upper surface of the convex portion has a width enough to form a wafer mounting concave portion. At the same time, when the concave portion is formed concentrically on the upper surface of the convex portion, a part of the upper surface of the convex portion continuous to the peripheral portion of the concave portion, that is, in FIG. Is the radius r
It is preferable to have an outer peripheral surface having a width X of (R−r =) 3 to 20 mm when formed in a circular shape. For example, the diameter 15
When forming a wafer mounting circular concave portion having a depth of 2 mm and a depth of 0.8 mm, a concentric convex portion having a circular upper surface having a diameter of 172 mm is formed, and an outer peripheral surface having a width (X) of about 10 mm is formed outside the peripheral portion of the concave portion. . If the width X exceeds 20 mm, the amount of impurities adhering to the upper surface of the remaining convex portion increases, and there is a possibility that a droop phenomenon of the SR value may occur at the peripheral portion of the wafer grown by the vapor phase. On the other hand, if the width X is less than 3 mm, the upper surface of the remaining convex portion is extremely thin, and the influence of the flat plate surface, which becomes high in temperature, is transmitted to the periphery of the counterbore portion. It is because there is a possibility that it becomes. The formation of the semiconductor wafer mounting recess can be performed in the same manner as in the conventional method.

The arrangement of the projections 4 formed as described above on the flat surface of the susceptor is not particularly limited. As shown in FIG. 1, the respective protrusions may be arranged with an interval, and even in such a case, as shown in FIG. 3 described later, two or more multiplex rings may be arranged on a flat plate surface. The number and system of the arrangement of these protrusions can be appropriately selected according to the vapor growth apparatus using the susceptor and the growth conditions. Further, the positional relationship between the respective convex portions is not particularly limited. For example, as shown in FIG. 2 in which a partial schematic plan view of another susceptor is shown, each convex portion may be arranged in a form (C) in which the outer circumferences are in contact with each other without a space, and It may be arranged in a form (D) in which the convex portions are continuously connected so as to overlap. In particular, the formation of the continuous form in FIG. 2D is preferable because the area of the upper surface of the remaining convex portion after the concave portion is formed on the upper surface of the convex portion is reduced and the amount of attached impurities is reduced.

The susceptor for vapor phase growth of the present invention has a structure as described above, except that a predetermined thin film is formed on a semiconductor wafer to be processed by a conventionally known chemical vapor reaction. It is used for a vapor phase growth method. The chemical vapor deposition method is already known in the art. Generally, a susceptor disposed in a reaction furnace is heated and heated by high-frequency heating or lamp heating to form a coating film such as a semiconductor wafer placed thereon. This is a method in which a predetermined film is formed on a substrate to be treated by heating a substrate and simultaneously introducing a reaction gas into a reaction furnace. In addition, a vapor phase growth apparatus used in this chemical vapor deposition method has been conventionally known, and there are a vertical type and a barrel type depending on the structure of a reaction furnace. Further, according to the number of wafers processed in a single process, the system is classified into a plurality of batch systems and a single wafer system. Although the type of susceptor used varies slightly depending on each method, the susceptor for vapor phase growth of the present invention can be applied to any method for performing the above-mentioned conventionally known chemical vapor deposition method.

The susceptor for vapor phase growth of the present invention can be formed in the same manner as the conventional one, except that it is formed in the above-described form. That is, the base material is made of carbon material,
The surface is covered with a silicon carbide (SiC) film. The SiC-coated carbon member has been conventionally used in a semiconductor manufacturing apparatus, and is not particularly limited, and a member formed in the same manner as in the related art can be used. Also,
The carbon substrate is not particularly limited, and conventionally known graphite and the like can be used. After forming the carbon substrate into the susceptor shape of the present invention as described above, the conventional S
It can be manufactured by forming the SiC film on the surface by performing the same treatment as the iC coating. The thickness of the SiC film formed on the carbon material of the present invention is not particularly limited,
The thickness may be about 40 to 150 μm as in the conventional susceptor. Both the surface roughness of the SiC film on the susceptor surface and the surface roughness (Ra) of the concave portion on which the wafer is placed are not particularly limited. For example, the susceptor plate surface is Ra
Can be set to 5 to 13 μm, and the concave surface can be set to 0.1 to 3 μm in Ra.

The susceptor of the present invention has a semiconductor wafer mounting concave portion formed on the upper surface of the convex portion projecting from the flat plate surface as described above. When a multi-layer epitaxial wafer having a plurality of film layers having different electrical characteristics such as an IGBT wafer is formed by epitaxial growth using this susceptor, for example, a large amount of high-concentration impurities at the time of the previous film deposition adhere to the susceptor surface. Also, since the temperature of the flat plate surface is higher than that of the upper surface of the convex portion where the concave portion is formed, the adhered impurities are removed by evaporation in the purging process of the switching process to the next film forming process. In this state, impurities on the surface of the susceptor flat plate are reduced. Therefore, the influence of the dopant concentration at the previous stage during each film formation is reduced, and each layer can be formed with desired electrical properties from the beginning of the film formation, and the vicinity of the interface of each layer of the obtained multilayer epitaxial wafer can be formed. Changes in electrical characteristics are steep. For example, when a profile of the SR value is taken in the depth direction of the epitaxial layer of the IGBT wafer, the SR value changes sharply near the interface between the two layers.
Further, there is no difference in SR value between the peripheral portion and the central portion of the IGBT wafer. Therefore, it is possible to obtain an epitaxial wafer which gives a device having uniform and excellent characteristics as a result.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to embodiments. However, the present invention is not limited by the following examples. Examples 1 to 5 and Comparative Example 1 (Preparation of susceptor for vapor phase growth)
A plate having a plate thickness (T) of 14 mm and a diameter (D) of 705 mm has a thickness (t) of 1,
Ten convex portions 4 of a cylindrical body having a radius (R) of 86 mm were formed at approximately equal intervals at 2, 3, 4, and 5 mm. Further, concentric concave portions 5 each having a radius (r) of 76 mm are formed on the upper surface of each convex portion 4 so as to have a width (X) of about 10 mm, and a susceptor substrate having substantially the same shape as that of FIG. Was formed. The surface of the susceptor substrate of the carbon material is subjected to SiC coating treatment in a vapor phase reaction chamber similar to the conventional one under a vapor phase growth condition of a reaction chamber temperature of 1200 ° C. or more and a room pressure of 1 Torr or less, and a SiC coating is formed on the surface. A formed susceptor was obtained.
The recesses of each of the obtained susceptors were polished by a conventional method to have a surface roughness (Ra) of about 1 to 15 μm. Also, without forming protrusions on the disk-shaped flat plate surface 2 of the same carbon material, ten concave portions having a radius (r) of 76 mm were similarly formed on the flat plate surface, and the surface was similarly coated with SiC. ,
A susceptor similar to the conventional susceptor in which the recess was polished was obtained (Comparative Example 1).

(Vapor Growth) Next, epitaxial growth is performed on a single crystal silicon wafer by using each susceptor prepared as described above in a device substantially similar to the vapor growth device shown in FIG. Was formed. FIG. 3 is a perspective explanatory view of the vertical chemical vapor deposition apparatus used in the present embodiment. In FIG. 3, the chemical vapor deposition apparatus 21 has a susceptor 1 rotatably disposed in a bell jar type reaction tube 22.
A source gas introduction nozzle 26 having a gas outlet 25 is provided upright at the center of the susceptor 1, an exhaust pipe 27 is provided below the reaction tube 22, and a high frequency coil 28 is provided below the susceptor 1. The wafer 23 placed on the susceptor 1 can be heated to a desired temperature.

Each of the susceptors 1 formed as described above is arranged in the vertical chemical vapor deposition apparatus 21 configured as described above, and the single-crystal silicon wafer 23 whose surface has been cleaned is placed in each of the recesses 5 of the susceptor 1. I attached it. Thereafter, the substrate is heated to 1800 to 1120 ° C. by the high-frequency coil 28 and the reaction tube 21 is heated.
From the gas outlet 25 into SiHCl as silane gas.
_{3. Using} a hydrogen gas as a carrier gas and phosphine (PH ₃ ) as a dopant gas, first introduce 7.5 g / min of SiHCl ₃ and a high concentration of 300 cc / min of PH ₃ gas to form a low-resistance first layer. After the film formation, the high concentration PH ₃ gas was replaced with hydrogen gas for 10 minutes. Thereafter, the temperature was lowered to room temperature, and the amount of impurities P per unit volume remaining on the flat plate surface 2 was measured. The results are shown in Table 1. The measurement was performed by secondary ion mass spectrometry (SI
MS) in an arbitrary area and a depth of 2.5 μm.

[0018]

[Table 1]

As is clear from the above Examples and Comparative Examples, in a susceptor having no convex portion, that is, a conventional susceptor having t = 0, the susceptor of the present invention having the convex portion has a residual impurity concentration on the flat plate surface. It can be seen that the number is increased by one digit as compared with. In addition, the height t of the projection is 1 mm, that is, 1 of the thickness (T) of the flat plate.
If it is less than / 7, the residual impurity concentration is higher than that of the susceptor having t of 2 mm. On the other hand, the height t of the projection is equal to the thickness T of the flat plate.
At t = 5 mm exceeding 2/7, cracks occurred in the susceptor. This is presumably because the temperature difference between the flat plate surface and the convex portion became extremely large.

Example 6 and Comparative Example 2 Using the susceptors obtained in Example 2 and Comparative Example 1, an epitaxial wafer having a two-layer structure was formed. That is, 10 silicon wafers were respectively mounted on the vertical vapor deposition apparatus in which the susceptors of Example 2 and Comparative Example 1 were respectively set in the same manner as in the above-described example, and the first layer of low resistance was formed first. After replacing the high-concentration PH ₃ gas with hydrogen gas for 10 minutes, subsequently, SiHCl ₃ was added at 30 g / min.
PH ₃ gas was introduced at a low concentration of 30 cc / min to form a high-resistance second layer to obtain two-layer epitaxial wafers. The SR value was measured for the central part and the peripheral part of the obtained two-layer epitaxial wafer. The resulting relationship between the SR value at the center and the depth direction is shown in FIG.

As is apparent from FIG. 4, the SR value in the depth direction of the epitaxial wafer obtained by using the susceptor provided with the convex portion of the present invention is near the boundary between the first layer and the second layer. It can be seen that there is no gradual decrease and the temperature drops sharply.
Further, there was no change in the SR value between the peripheral portion and the central portion in the wafer plane, and it was apparent that epitaxial growth was performed almost uniformly in a two-layer structure. On the other hand, the SR value in the depth direction of the epitaxial wafer obtained by using the same susceptor as the conventional one gradually decreases near the boundary surface between the first layer and the second layer, and the SR value of the first layer and the second layer decreases. There is no clear distinction between the layers, and it can be seen that there is a portion (drip) where the SR value decreases from the first layer to the second layer. Also,
In the SR value in the depth direction, sagging occurred more in the peripheral portion than in the central portion of the wafer.

[0022]

The susceptor for vapor phase growth according to the present invention has a projection with a predetermined thickness provided on a flat plate surface, and a recess of a counterbore for mounting a semiconductor wafer on the projection. For this reason, when performing epitaxial film formation in multiple layers, at the time of gas purging in each film formation switching step, the flat plate surface temperature is lower than that of the upper surface of the convex portion on which the semiconductor wafer to be coated is mounted.
Since the temperature can be relatively high, the dopant component attached to the flat plate surface can be easily evaporated and scattered and removed. Therefore, an epitaxial film having predetermined electrical characteristics can be formed from the beginning without being affected by the dopant concentration in the processing gas at the preceding stage at the time of each film formation. For example, the first film grown epitaxially on an IGBT wafer having a two-layer structure can be formed. A rapidly changing resistance difference can be formed between the layer and the second layer, and sag does not occur in the profile of the SR value in the depth direction of the wafer. Further, the difference in characteristics between the central portion and the peripheral portion of the wafer is reduced, and devices using these wafers have uniform and excellent characteristics.

[Brief description of the drawings]

FIG. 1 is a schematic plan view (A) of an embodiment of a susceptor for vapor phase growth of the present invention, and an end view (B) of a cross section taken along line BB of FIG.

FIG. 2 is a schematic plan view of another embodiment of the susceptor for vapor phase growth of the present invention.

FIG. 3 is an explanatory perspective view of a bell jar type chemical vapor deposition apparatus used in an embodiment of the present invention.

FIG. 4 is a profile showing an SR value with respect to a depth direction of a two-layered epitaxial wafer obtained in Examples and Comparative Examples of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 susceptor 2 flat plate surface 3 gas nozzle through hole 4 convex portion 5 concave portion 10 carbon base material 11 SiC film 21 vertical vapor deposition apparatus 22 bell jar type reaction tube 23 single crystal silicon wafer 25 gas outlet 26 source gas introduction nozzle 27 exhaust Tube 28 High frequency coil

Claims (3)

[Claims] 1. A susceptor for vapor phase growth comprising a carbon substrate surface coated with a SiC film, the susceptor having one or more projections projecting from the surface of a flat plate, and a semiconductor wafer mounted on an upper surface of the projection. A susceptor for vapor phase growth, wherein a recess is formed. 2. The method according to claim 1, wherein the thickness of the projection is 1 / th of the thickness of the flat plate.
The susceptor for vapor phase growth according to claim 1, wherein the ratio is 7 to 2/7. 3. The susceptor for vapor phase growth according to claim 1, wherein a radius of the upper surface of the convex portion is formed to be 3 to 20 mm larger than a radius of the concave portion.