JP4874743B2 - Gallium nitride compound semiconductor vapor phase growth system - Google Patents

Description

The present invention relates to a semiconductor film vapor phase growth apparatus, and more particularly, a gallium nitride-based compound semiconductor including a susceptor for placing a substrate, a heater for heating the substrate, a source gas introduction unit, and a reaction gas discharge unit. The present invention relates to a vapor phase growth apparatus.

  In recent years, the demand for gallium nitride-based compound semiconductors has been increasing rapidly as an element such as a light-emitting diode or a laser diode, mainly in the lighting field. As a method for producing a gallium nitride compound semiconductor, for example, an organic metal gas such as trimethylgallium, trimethylindium, or trimethylaluminum is used as a group III metal source, ammonia is used as a nitrogen source, and sapphire is set in advance in a reaction chamber. A method of forming a semiconductor film of a gallium nitride compound on a substrate by vapor phase growth (hereinafter sometimes referred to as MOCVD method) is known.

  The apparatus for producing the gallium nitride compound semiconductor includes a susceptor on which the substrate is placed, a heater for heating the substrate, a source gas introduction unit, a reaction gas discharge unit, and a susceptor rotating shaft that supports the susceptor. A horizontal type or vertical type vapor phase growth apparatus is known. In such a vapor phase growth apparatus, a substrate is placed on a susceptor and heated by a heater, and then two or more kinds of gases containing the above-mentioned raw materials are supplied from the horizontal direction or the vertical direction with respect to the surface of the substrate. Thus, a semiconductor film is formed on the substrate by vapor phase growth.

In the manufacture of gallium nitride-based compound semiconductors, the substrate is heated to a high temperature of 1000 ° C. or higher, and the corrosive source gas is supplied to the surface of the substrate. In addition, heat resistance and corrosion resistance are required. Conventionally, various heaters applicable to high temperature corrosive gas atmospheres, or vapor phase growth apparatuses using the same have been developed. For example, Japanese Patent Laid-Open No. 5-206100 discloses a semiconductor manufacturing apparatus using a heater protected by a quartz tube. JP-A-8-17745 discloses a heater coated with high-purity pyrolytic graphite and a heater coated with silicon carbide. Japanese Patent Application Laid-Open No. 11-233244 discloses a CVD apparatus hot plate in which a heater is incorporated in one of three aluminum plate layers and a reinforcing material is incorporated in the other. Japanese Patent Application Laid-Open No. 2003-133225 discloses a heater formed on one side or inside of a plate-like body made of nitride ceramic or carbide ceramic.
JP-A-5-206100 JP-A-8-17745 JP-A-11-233244 JP 2003-133225 A

  However, even in the case of a heater coated with a heat-resistant and corrosion-resistant material as described above, the coefficient of thermal expansion between the constituent material of the heat generating part and the heat-resistant and corrosion-resistant material after repeated use at room temperature and 1100 to 1200 ° C. Due to the difference, the heater is deformed and cracked, and the effect of covering the heat-resistant and corrosion-resistant material is reduced. Furthermore, in addition to such a situation, the use of 1100-1200 ° C. and 10-50% ammonia atmosphere deteriorates these materials in a relatively short period of time, and the heaters run out, so the heaters must be replaced frequently. was there.

It is also conceivable to place a quartz plate that transmits the heat rays of the heater across the space from the heater and shield the corrosive gas from the heater. However, plastic deformation of the quartz plate occurs at a high temperature as described above, and the plastic deformation gradually increases as heating and cooling are repeated. For example, the quartz plate hangs down and comes into contact with other components in the reaction chamber, and the apparatus is damaged. Therefore, the quartz plate had to be replaced in a relatively short time. In particular, in a large apparatus configured to vapor-phase grow simultaneously on a plurality of substrates, a large quartz plate corresponding to the scale of the apparatus must be used, and the problem of plastic deformation of quartz tends to increase.
Accordingly, the problem to be solved by the present invention is that the quality of the semiconductor film is adversely affected even when a vapor phase growth reaction using a gas having high corrosivity at a high temperature such as a gallium nitride compound semiconductor is performed. It is another object of the present invention to provide a vapor phase growth apparatus capable of stably forming a film over a long period of time.

As a result of intensive studies to solve these problems, the present inventors have established a light-transmitting ceramic plate such as a quartz plate held or reinforced by a support member with a space between the heater and the substrate. It has been found that by arranging and shielding the corrosive gas from the heater, the heater can be protected from the corrosive gas at high temperature, and the vapor phase growth apparatus of the present invention has been reached. That is, the present invention includes a susceptor for mounting a substrate, a heater for heating the substrate, a source gas introduction unit for supplying source gas to the substrate, and a reaction gas discharge unit, and mounting the heater and the substrate A light-transmitting ceramic plate that is held or reinforced from below by a support member comprising a peripheral member, a central member, and a member that couples these members, with a space between the heater and a space. A gallium nitride system comprising an annular light-transmitting ceramic having a central hole in the center of the plate, the light-transmitting ceramic plate being composed of a plurality of fan-shaped light-transmitting ceramic plate pieces This is a compound semiconductor vapor phase growth apparatus.

  In the vapor phase growth apparatus of the present invention, the heater is not directly covered with the heat-resistant and corrosion-resistant material. There is no problem with the difference in thermal expansion coefficient, and a light-transmitting ceramic plate such as quartz, which has a relatively low softening point, is held or reinforced by a support member and provided between the heater and the substrate. Even below, plastic deformation of the ceramic plate can be almost ignored, and the replacement frequency of the ceramic plate can be greatly reduced. Therefore, the vapor phase growth apparatus of the present invention suppresses disconnection of the heater even when performing a vapor phase growth reaction using a gas having high corrosivity at a high temperature such as a gallium nitride compound semiconductor. This makes it possible to perform vapor phase growth with little change over time and good reproducibility.

INDUSTRIAL APPLICABILITY The present invention is applied to a gallium nitride compound semiconductor vapor phase growth apparatus including a susceptor for mounting a substrate, a heater for heating the substrate, a source gas introduction unit for supplying source gas to the substrate, and a reaction gas discharge unit. The Further, the present invention can be applied to any vapor phase growth apparatus in which a gas containing a raw material is supplied from the horizontal direction, supplied from above, or supplied from below. Note that, in the MOCVD method in which a source gas is blown onto a high-temperature substrate, a method of supplying the source material from the lower side of the substrate with the film-forming surface of the substrate facing down is desirable in that the influence of thermal convection is small. Further, in the vapor phase growth apparatus of the present invention, the formation of a gallium nitride compound semiconductor film requiring a high temperature of 1000 ° C. or more as the vapor growth temperature, and further the gallium nitride compound semiconductor film on a plurality of substrates In the case of film formation, the disconnection of the heater can be suppressed, and the effect of the present invention can be exhibited sufficiently in that stable vapor phase growth can be achieved over a long period of time.

Hereinafter, although the vapor phase growth apparatus of this invention is demonstrated in detail based on FIGS. 1-7, this invention is not limited by these.
1 and 2 are vertical sectional views showing an example of the vapor phase growth apparatus of the present invention. FIG. 3 is an enlarged cross-sectional view showing an example of a portion in which the outer peripheral end of the annular light-transmitting ceramic plate or the peripheral end of the center hole is held by a support member in the vapor phase growth apparatus of the present invention. FIG. 4 is an enlarged cross-sectional view showing an example of a portion in which a central portion of an annular or disk-shaped light-transmitting ceramic plate is held by a support member in the vapor phase growth apparatus of the present invention. FIG. 5 is a configuration diagram showing an example of a light-transmitting ceramic plate in the vapor phase growth apparatus of the present invention. 6 and 7 are configuration diagrams showing examples of support members for holding or reinforcing a light-transmitting ceramic plate from below in the vapor phase growth apparatus of the present invention.

As shown in FIGS. 1 and 2, the vapor phase growth apparatus of the present invention includes a susceptor 2 for placing a substrate 1, a heater 3 for heating the substrate 1, and a source gas for supplying a source gas to the substrate 1. It has an introduction part 4 and a reaction gas discharge part 5, and is held or reinforced by a support member 6C from below as shown in FIGS. 3 and 4 between the heater 3 and the mounting position of the substrate 1. A vapor phase growth apparatus including a light-transmitting ceramic plate 7. Further, as shown in FIG. 1, a gear portion 8 for revolving the susceptor 2 (a portion where gears meshing with each other on the outer edge of the susceptor and the facing surface contacting it), a heat insulating plate 9, a gas guide member 10 and the like are provided as appropriate. be able to. As shown in FIGS. 1 and 2, the susceptor 2 can be configured to mount a plurality of substrates 1. In addition, as shown in FIG. 2, a susceptor rotating shaft 11 can be provided instead of the gear portion 8 of FIG.

In the present invention, the light-transmitting ceramic plate 7 is provided with a space from the substrate 1, the susceptor 2, or the heater 3. The light-transmitting ceramic plate 7 is provided so that the source gas introduced from the source gas introduction unit 4 or the reaction gas generated by the reaction thereof does not reach the surface of the heater 3. . In the conventional vapor phase growth apparatus, since there is no light-transmitting ceramic plate 7, for example, the raw material gas and the reactive gas enter from the outer peripheral portion of the revolving susceptor 2 and the outer peripheral portion of the rotating substrate 1. And reach the heater 3. In the present invention, the outer peripheral end support member 6A mainly serves to support the light-transmitting ceramic plate 7 from the side surface, and the center support member 6B mainly serves to support the light-transmitting ceramic plate 7 at the center portion. The support member 6C from below mainly serves to reinforce the light-transmitting ceramic plate 7 and support it from below.

In the vapor phase growth apparatus of the present invention, the light-transmitting ceramic plate 7 is usually annular or disk-shaped as shown in the block diagram of FIG. The shape may be a quadrangle, a pentagon, a hexagon, an octagon, a polygon, or the like. When the light-transmitting ceramic plate 7 is annular, a part or all of the outer peripheral end 12 is usually held by an outer peripheral end supporting member 6A and a supporting member 6C from below as shown in FIG. For example, as shown in FIG. 4B, a part or all of the peripheral end 13 is held by a center support member 6B and a support member 6C from below . Further, in the case of a disc shape without holes, usually, a part or all of the outer peripheral end 12 is held by an outer peripheral end supporting member 6A and a supporting member 6C from below as shown in FIG. For example, as shown in FIG. 4A, a part or the whole is held by a center support member 6B and a support member 6C from below . The method of holding the light-transmitting ceramic plate 7 by the support member is not particularly limited. For example, as shown in FIGS. 3 and 4, a method of holding the light-transmitting ceramic plate 7 using a bolt, an outer peripheral end support member 6A. A method of holding by the center support member 6B can be performed.

  In the example of the vapor phase growth apparatus shown in FIGS. 1 and 2, the heater 3 is surrounded by the heat insulating plate 9, the light-transmitting ceramic plate 7, and the supporting members 6A and 6B. It is preferable that an inlet pipe for introducing an inert gas is connected to the structure surrounding the heater so that the structure can be filled with the inert gas. Examples of the inert gas include nitrogen gas, helium gas, neon gas, argon gas, krypton gas, xenon gas, and radon gas, and nitrogen gas is usually used frequently. Further, it is desirable that the structure has a highly sealed structure so that a highly corrosive gas used for film formation does not easily enter. The gap between the heater 3 and the light transmissive ceramic plate 7 and the gap between the light transmissive ceramic plate 7 and the susceptor 2 are usually 1 to 20 mm, preferably 3 to 15 mm, and more preferably 5 to 10 mm. If the thickness is 1 to 20 mm, the heater can be protected. When the gap exceeds 20 mm, the effect of the heater is reduced.

Moreover, although the ceramic plate 7 illustrated in FIG. 5 has an annular shape and a disc shape, a large temperature distribution may occur in the in-plane direction depending on the actual use situation. In such a case, depending on the thermal expansion coefficient of the material used for the ceramic plate 7, a large elastic deformation may occur, or damage due to this deformation may occur. For example, when a ceramic plate having a diameter of 600 mm is maintained at a temperature 1000 ° C. higher than room temperature and the thermal expansion coefficient of the material is 5 × 10 ⁻⁶ / ° C., the ceramic plate expands by 3 mm in the diameter direction. Therefore, in such a case, the holding portion of the light-transmitting ceramic plate 7 needs to have a structure that does not cause a problem even if such thermal deformation occurs. In order to avoid such a problem, it is desirable to divide the ceramic plate 7 so that thermal deformation can be mitigated. As a specific dividing method, in the case of an annular or disk-shaped ceramic plate, a method of dividing it into concentric circles or a fan shape, or dividing into concentric circles, and partially or all of them in the circumferential direction For example, there may be a method of dividing the shape into a fan shape and then partially or entirely dividing it into a radial shape.

  In the vapor phase growth apparatus of the present invention shown in FIG. 1, the light-transmitting ceramic plate 7 is fixed at the peripheral part and the central part by the supporting members 6A and 6B as described above, so that only the outer peripheral end part is supported. Compared with the case where it is held by a member, it is possible to suppress sagging due to plastic deformation of the light-transmitting ceramic plate. As a result, for example, when a quartz plate is used as the light-transmitting ceramic plate, there is no risk of contact or damage to other parts due to the drooping of the quartz plate, and stable vapor phase growth can be performed for a long time.

In the vapor phase growth apparatus of the present invention, as the structure of the support member 6C, for example, as shown in FIGS. 6 and 7 (1) (2), the outer peripheral member 14, the central member 15, and the member 16 that couples them, The structure which consists of the connection member 17 of geometric pattern shape can be illustrated. The outer peripheral member 14 and the central member 15 mainly serve to reinforce and support the light-transmitting ceramic plate 7 from below, and the connecting member 16 or the geometrically-shaped connecting member 17 is mainly a light-transmitting ceramic plate. 7 serves to suppress sagging due to plastic deformation. Examples of the shape of the coupling member 16 or the geometric pattern member 17 include a mesh shape, a radial shape, a spiral shape, a vertical stripe shape, a horizontal stripe shape, and a combination thereof. The shape of the outer periphery of the support member 6 C is normally a circular are those that meet the light-transmitting ceramic plate, without being limited thereto, square, pentagonal, hexagonal, octagonal, polygonal, etc. It may be. Such a support member 6 </ b> C is usually the same as or close to the outer diameter of the light-transmitting ceramic plate 7. The support member 6C is desirably divided and manufactured so that thermal deformation can be mitigated in the same manner as the light-transmitting ceramic plate 7. The specific dividing method is the same as that of the light-transmitting ceramic plate 7.

In the vapor phase growth apparatus of the present invention, the constituent material of the light-transmitting ceramic plate is usually silicon oxide (including quartz), alumina, magnesia, yttrium oxide, MgAl ₂ O ₄ , aluminum oxynitride, etc. Oxide-based ceramics or nitride-based ceramics such as aluminum nitride are used, but are not limited to these, have heat resistance to a temperature of about 1200 ° C., transmit heat rays emitted from the heater, and feed gas In addition, any material having corrosion resistance to the reaction gas can be used. The thickness of the light-transmitting ceramic plate is usually about 0.5 to 10 mm, the outer diameter is usually about 100 to 1000 mm, and when holes are provided, the hole diameter is usually about 2 to 200 mm.

In addition, as a constituent material of the support member, metals such as carbon steel, manganese steel, chromium steel, molybdenum steel, stainless steel, nickel steel, tungsten steel, alloys, metal oxides, ceramics, and carbon materials are used. It is done.
In particular, a heat-resistant member having a mechanical strength at 800 to 1300 ° C. superior to the light-transmitting ceramic plate 7 is used for the support member 6C. The constituent materials of such a heat-resistant support member include metals such as molybdenum and tungsten, heat-resistant alloys such as Inconel, metal oxides such as alumina, aluminum oxynitride, magnesia, and zirconia, boron nitride, silicon nitride, and nitride Nitride ceramics such as zirconium, titanium nitride, tungsten nitride, and aluminum nitride, carbide ceramics such as boron carbide, silicon carbide, zirconium carbide, titanium carbide, tungsten carbide, and tantalum carbide, boron nitride, boron carbide, titanium boride, etc. And boride-based ceramics and carbon materials.

  In addition, as a carbon material, in the case of normal isotropic graphite, the corrosion resistance may not be high, carbon obtained by vapor phase growth (pyrolytic carbon), or graphite coated with pyrolytic carbon, It is preferable to use glassy carbon, graphite coated with glassy carbon, graphite coated with tantalum carbide, graphite coated with silicon carbide, or the like. Two or more of these may be used. Further, when the support member 6C is not light-transmitting, the support member 6C should have a cross-sectional area viewed from the heater as small as possible in order to prevent the heat rays from the heater from efficiently reaching the susceptor. However, if the cross-sectional area viewed from the heater is reduced, the mechanical strength is reduced, which is not preferable. Examples of the shape of a preferable reinforcing material when a general heat-resistant metal is used for the support member 6C include linear and net-like ones having a diameter of 0.5 mm or more and 5 mm or less, as viewed from the heater. Examples of a preferable cross-sectional area of the reinforcing material include 50% or less, preferably 40% or less, and more preferably 20% or less.

By the way, quartz has a very small thermal expansion coefficient among light-transmitting ceramics. Therefore, even if a large member is produced, thermal elastic deformation is small and can be suitably used in the present invention.
The constituent material of the support member 6C is roughly classified into a material having good light transmission and a material having low light transmission. Examples of the former include sapphire, alumina, aluminum oxynitride, aluminum nitride, and the like, and examples of the latter include a refractory metal. The heat-resistant metal is resistant to thermal shock and mechanical shock, and can be suitably used as the support member of the present invention in that respect. Furthermore, the reinforcing effect can be improved without substantially impairing the transmission of heat rays by installing the above-described reinforcing material having good light transmitting property between the supporting member and the light transmitting ceramics. In this respect, it can be suitably used in the present invention. Furthermore, in such a structure, even if the thermal expansion coefficient of the light-transmitting reinforcing material is not small, a number of divided reinforcing materials are combined and further supported by a reinforcing material having a low light-transmitting material. It is also preferable in that it can be.

  Depending on the operating temperature and operating atmosphere, quartz may evaporate at high temperatures. For example, when quartz is used as a light-transmitting ceramic and heated to about 1100 ° C. or higher in a hydrogen atmosphere, quartz powder may adhere to the susceptor. In such a case, the surface of the susceptor on the heater side changes color and the absorption factor of the heat rays changes, so that the power required for heating the susceptor changes with time, and stable film formation over a long period of time becomes impossible. When a light-transmitting ceramic material other than quartz is used together with quartz, it has an effect of suppressing the evaporation of quartz and enables stable film formation for a long period of time. Therefore, it is suitably used as a specific example of the present invention. be able to.

  Specific examples of the heater material that can be used in the present invention include refractory metals such as molybdenum and tungsten, and heat-resistant conductive ceramics such as graphite and silicon carbide. Since silicon carbide is sublimable in a high-temperature reducing atmosphere, it is desirable to keep it in an inert gas atmosphere such as nitrogen or argon during heating. According to the present invention, it is possible to use a heater having a low corrosion resistance against ammonia at a high temperature such as graphite, but by coating it with an ammonia-resistant material, it can be used against unexpected situations. Reliability can be increased. Specific examples of the ammonia-resistant material suitable for graphite used as a heater include pyrolytic carbon, glassy carbon, tantalum carbide, silicon carbide, boron nitride, and the like.

  EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not limited by these.

(Production of vapor phase growth equipment)
A stainless steel reaction vessel is provided with a disk-shaped susceptor (diameter 560 mm, thickness 11 mm), a heater, a source gas introduction part, a gas guide member, and a reaction gas discharge part. Further, an outer peripheral end support member 6A (nitriding) 1 is provided with an annular light-transmitting ceramic plate (quartz plate) in which the outer peripheral end is held by boron) and the peripheral end of the central hole is held by the center support member 6B (boron nitride). A device was made. The light-transmitting ceramic plate had a diameter of 650 mm, a thickness of 3 mm, and a center hole diameter of 32 mm. In addition, by a peripheral member (outer diameter 650 mm, width 30 mm, thickness 3 mm) made of carbon material, a central member (outer diameter 62 mm, width 30 mm, thickness 3 mm), and a mesh structure (interval 10 mm) made of molybdenum. Using the support member 6C as shown in FIG. 6 (3), the light-transmitting ceramic plate was supported and reinforced from below. The gap between the light transmissive ceramic plate and the heater was 7 mm, and the gap between the light transmissive ceramic plate and the susceptor was also 7 mm.

(Heating experiment)
The following heating experiment was performed using this vapor phase growth apparatus. That is, after replacing the reaction chamber with nitrogen gas, the temperature of the thermocouple installed near the heater was heated to 1200 ° C., and this temperature was maintained for a total of 18 hours.
After the temperature was lowered to room temperature, the sagging state of the light-transmitting ceramic plate was measured. As a result, the sagging of the light-transmitting ceramic plate was hardly observed, and the maximum value was 1 mm or less.

(Corrosion resistance experiment)
Next, after heating so that the temperature of the thermocouple installed in the vicinity of the heater was 1200 ° C., a mixed gas of ammonia gas (20 vol%) and hydrogen gas (80 vol%) was circulated in the reaction chamber for 200 hours.
After the temperature was lowered to room temperature, the surface condition of the heater was measured. As a result, no damage due to corrosive gas (ammonia gas) could be confirmed on the surface of the heater covered with the boron nitride film.
Further, the heater coated with the boron nitride film was replaced with a graphite heater whose surface was not coated with ammonia, and a vapor phase growth apparatus was manufactured, and the same corrosion resistance experiment was performed. However, similarly, no damage due to corrosive gas (ammonia gas) could be confirmed on the surface of the heater.

[Examples 2 to 4]
In the manufacture of the vapor phase growth apparatus of Example 1, the constituent materials of the supporting members 6A and 6B that hold the outer peripheral end of the light-transmitting ceramic plate and the peripheral end of the center hole are stainless steel and alumina, stainless steel and inconel, and stainless steel, respectively. A vapor phase growth apparatus was manufactured in the same manner as in Example 1 except that the carbon material was used.
Each heating experiment was performed in the same manner as in Example 1 except that these vapor phase growth apparatuses were used. As a result, almost no sagging of the light-transmitting ceramic plate was observed, and the maximum value was 1 mm or less.

[Examples 5 to 8]
In the manufacture of the vapor phase growth apparatus of Example 1, the structure of the support member 6C that supports the light-transmitting ceramic plate from below is shown in FIGS. 6 (2) (molybdenum wire diameter 3 mm) and FIG. 6 (4) (mesh). Vapor phase growth apparatus in the same manner as in Example 1, except that the distance is 10 mm), FIG. 7 (1) (molybdenum wire diameter 3 mm), and FIG. 7 (2) (molybdenum wire diameter 3 mm). Was made.
Each heating experiment was performed in the same manner as in Example 1 except that these vapor phase growth apparatuses were used. As a result, almost no sagging of the light-transmitting ceramic plate was observed, and the maximum value was 1 mm or less.

[Examples 9 to 11]
In the manufacture of the vapor phase growth apparatus of Example 1, the constituent material of the coupling member 16 of the supporting member 6C that supports the light-transmitting ceramic plate from below is changed to tungsten, Inconel, and boron nitride, respectively, and is the same as Example 1. Thus, a vapor phase growth apparatus was manufactured.
Each heating experiment was performed in the same manner as in Example 1 except that these vapor phase growth apparatuses were used. As a result, almost no sagging of the light-transmitting ceramic plate was observed, and the maximum value was 1 mm or less.

[Examples 12 to 14]
In the production of the vapor phase growth apparatus of Example 1, a vapor phase growth apparatus was produced in the same manner as in Example 1 except that the light-transmitting ceramic plates were replaced with sapphire, alumina, and aluminum oxynitride, respectively.
Each heating experiment was performed in the same manner as in Example 1 except that these vapor phase growth apparatuses were used. As a result, almost no sagging of the light-transmitting ceramic plate was observed, and the maximum value was 1 mm or less.

[Example 15]
An annular susceptor (diameter 560 mm, thickness 11 mm), a heater, a source gas introduction part, a gas guide member, and a reaction gas discharge part are provided inside a stainless steel reaction vessel, and the outer peripheral end is supported by the outer peripheral end support member 6A. Then, an annular light-transmitting ceramic plate in which the peripheral end of the center hole was held by the center support member 6B was provided to manufacture a vapor phase growth apparatus as shown in FIG. Further, the light-transmitting ceramic plate was made by superimposing quartz and sapphire (thickness was 1.5 mm each), and sapphire was set on the lower side. Otherwise, a vapor phase growth apparatus was manufactured in the same manner as in Example 1.
Each heating experiment was performed in the same manner as in Example 1 except that this vapor phase growth apparatus was used. As a result, almost no sagging of the light-transmitting ceramic plate was observed, and the maximum value was 1 mm or less.

[ Comparative Example 1 ]
An annular susceptor (diameter 280 mm, thickness 11 mm), a heater, a source gas introduction part, a gas guide member, and a reaction gas discharge part are provided inside a stainless steel reaction vessel, and support members 6A and 6B (boron nitride) 1 was provided with a disc-shaped light-transmitting ceramic plate (quartz plate) having no holes in the central portion where the outer peripheral end and the central portion were held, and a vapor phase growth apparatus as shown in FIG. 1 was manufactured. The light-transmitting ceramic plate had a diameter of 300 mm and a thickness of 5 mm. Moreover, the heat resistant support member 6C was not used. The gap between the light transmissive ceramic plate and the heater was 7 mm, and the gap between the light transmissive ceramic plate and the susceptor was also 7 mm. A heating experiment was conducted in the same manner as in Example 1 except that this vapor phase growth apparatus was used. As a result, the maximum sag of the light-transmitting ceramic plate was about 1 to 2 mm.

[ Comparative Examples 2 to 4 ]
In the production of the vapor phase growth apparatus of Comparative Example 1, a vapor phase growth apparatus was produced in the same manner as in Comparative Example 1 except that the light-transmitting ceramic plate was replaced with sapphire, alumina, and aluminum oxynitride, respectively. Each heating experiment was performed in the same manner as in Example 1 except that these vapor phase growth apparatuses were used. As a result, the maximum sag of the light-transmitting ceramic plate was about 1 to 2 mm.

[Comparative Example 5 ]
In the production of the vapor phase growth apparatus of Example 1, a vapor phase growth apparatus was produced in the same manner as in Example 1 except that the light-transmitting ceramic plate was not provided. The following corrosion resistance experiment was performed using this vapor phase growth apparatus. That is, after heating the thermocouple installed in the vicinity of the heater to 1200 ° C., a mixed gas of ammonia gas (20 vol%) and hydrogen gas (80 vol%) was circulated in the reaction chamber for 20 hours. After the temperature was lowered to room temperature, the surface condition of the heater was measured. As a result, it was confirmed that a large number of minute holes (diameter of about 1 mm) were generated by the corrosive gas (ammonia gas) on the surface of the heater covered with the boron nitride film.

The results of summarizing the heating experiments of Examples 1 to 15 and Comparative Examples 1 to 4 are shown in Tables 1 and 2, respectively, and the results of the corrosion resistance experiment of Example 1 and Comparative Example 5 are shown in Table 3, respectively. As described above, it has been found that the vapor phase growth apparatus of the present invention using the support member 6C can suppress sagging due to plastic deformation.

Vertical sectional view showing an example of the vapor phase growth apparatus of the present invention Vertical sectional view showing an example of a vapor phase growth apparatus other than FIG. 1 of the present invention An enlarged sectional view showing an example of a portion in which the outer peripheral end of the annular light-transmitting ceramic plate or the peripheral end of the center hole is held by a support member An enlarged cross-sectional view showing an example of a portion in which a central portion of an annular or disc-shaped light-transmitting ceramic plate is held by a support member Configuration diagram showing examples of light-transmitting ceramic plates Configuration diagram showing an example of a support member for holding or reinforcing a light-transmitting ceramic plate from below Configuration diagram showing an example of a support member other than FIG. 6 that holds or reinforces a light-transmitting ceramic plate from below.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Board | substrate 2 Susceptor 3 Heater 4 Raw material gas introduction part 5 Reaction gas discharge part 6A Outer peripheral edge support member 6B Center part support member 6C Support member from the bottom 7 Light-transmitting ceramic board 8 Gear part 9 Heat insulation board 10 Gas guide member 11 Susceptor Rotating shaft 12 Outer peripheral end 13 Peripheral end of center hole 14 Outer peripheral member 15 Central member 16 Connecting member 17 Geometric pattern-shaped connecting member

Claims (6)

A susceptor for mounting the substrate, a heater for heating the substrate, a source gas introduction unit for supplying source gas to the substrate, and a reactive gas discharge unit, between the heater and the substrate mounting position, A light-transmitting ceramic plate that is held or reinforced from below by a support member comprising a peripheral member, a central member, and a member that couples these members with a space from the heater, and is centered in the center of the light-transmitting ceramic plate It has an annular light-transmitting ceramic that forms holes ,
The light-transmitting ceramic plate is composed of a plurality of fan-shaped light-transmitting ceramic plate pieces . The light-transmitting ceramic plate has a gap between the outer peripheral end of the light-transmitting ceramic plate and the support member that allows the light-transmitting ceramic plate to expand and contract in the radial direction away from the center hole by thermal deformation. The vapor phase growth apparatus according to claim 1, wherein the vapor deposition apparatus is held or reinforced from below by a support member .   The vapor phase growth apparatus according to claim 1 or 2, wherein the constituent material of the light-transmitting ceramic plate is sapphire, alumina, or aluminum oxynitride.   The vapor phase growth apparatus according to claim 1 or 2, wherein the constituent material of the support member is one or more selected from metals, alloys, metal oxides, ceramics, and carbon materials.   The vapor phase growth apparatus according to claim 1 or 2, wherein the susceptor is configured to place a plurality of substrates.   The vapor phase growth apparatus according to claim 1 or 2, wherein means for introducing an inert gas is provided in a space between the light-transmitting ceramic plate and the heater.

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