JP2015002190A - Vapor phase growth device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vapor phase growth device capable of easily detecting a wear amount of a gear, in a vapor phase growth device including a substrate holder having a gear in an outer periphery, a susceptor having a gear in an outer periphery, and a rotating plate having a gear in an outer periphery to transmit a rotational drive force from the outside to the substrate holder or the susceptor.SOLUTION: In a vapor phase growth device as mentioned above, a mark for visually detecting a wear amount is provided at a tip of a gear of at least one rotating object selected from among a substrate holder, a susceptor and a rotating plate. The vapor phase growth device preferably includes a view port through which the mark provided to the rotating objects can be visually recognized from the outside.

Description

  The present invention relates to a vapor phase growth apparatus, and more specifically, a substrate holder having a gear on the outer periphery, a susceptor having a gear on the outer periphery, and a gear having an outer periphery to transmit a rotational driving force from the outside to the substrate holder or the susceptor. The present invention relates to a vapor phase growth apparatus provided with a rotating plate for the purpose.

As a method for growing a crystal film on a substrate, there is a chemical vapor deposition (CVD) method or the like, and a CVD method involving substrate heating is known as a thermal CVD method or the like. In recent years, vapor deposition performed by heating a substrate at a high temperature (for example, 1000 ° C. or more) has increased, and vapor deposition of a group III nitride semiconductor for producing a blue or ultraviolet LED or a blue or ultraviolet laser diode has also been performed. One of them.
For example, the growth of a group III nitride semiconductor crystal film was heated to a high temperature of 1000 ° C. or higher using an organic metal gas such as trimethylgallium, trimethylindium, or trimethylaluminum as a group III metal source and ammonia as a nitrogen source. In some cases, the thermal CVD method is used in which a crystal film is vapor-phase grown on a substrate such as silicon (Si), sapphire (Al ₂ O ₃ ), or gallium nitride (GaN).

In such vapor phase growth, by rotating the substrate during the vapor phase growth, it is possible to grow a crystal film having a uniform film thickness and quality within the substrate surface. In addition, by rotating and revolving the substrate during vapor phase growth, a uniform film thickness and film quality can be obtained not only within the same substrate surface but also between the substrates.
For example, in the vapor phase growth apparatus described in Patent Documents 1 to 3, a plurality of substrate holders are rotatably held by a susceptor, and the substrate can revolve by rotation of the substrate holder and the susceptor. The vapor phase growth apparatus described in Patent Literature 1 includes a substrate holder provided with gears on the outer periphery, and the vapor phase growth apparatus described in Patent Literature 2 includes a substrate holder provided with gears on the outer periphery, and A susceptor is provided, and the substrate holder and the susceptor are rotated by receiving a rotational driving force from the outside with such a gear. In addition, in the vapor phase growth apparatus described in Patent Document 3, in addition to the substrate holder and susceptor for rotating and revolving the substrate, a gear is provided on the outer periphery, and an external rotational driving force is applied to the substrate holder or susceptor. A rotating plate for transmission is also provided.

JP 2009-99770 A Japanese Patent No. 4533766 JP 2012-227231 A

In such a vapor phase growth apparatus, when wear of a gear provided on a rotating object such as a substrate holder, a susceptor, and a rotating plate progresses, a problem occurs in the meshing of the gear, and the quality of the crystal film is adversely affected. As a result, a gear that has been worn must be replaced with a new one before a meshing failure occurs. These rotating gears are placed under the high temperature associated with the heating of the substrate and often come into contact with the reactive source gas, and wear tends to proceed faster than in a normal environment. I had to determine the time for replacement. Therefore, there has been a demand for a simple means that can easily detect the amount of wear of the gear of the rotating object as described above and can determine that the replacement time has been reached.
Therefore, the problem to be solved by the present invention is to provide a vapor phase growth apparatus as described above, which can easily detect the amount of wear of a gear of a rotating object.

  As a result of intensive studies to solve these problems, the present inventors have found that the tip of the gear of at least one rotating object selected from the substrate holder, susceptor, and rotating plate provided in the vapor phase growth apparatus is worn. The inventors have found that the above-mentioned problems can be solved by providing a mark for visually detecting the amount, and have reached the vapor phase growth apparatus of the present invention.

  That is, the present invention includes a substrate holder having a gear on the outer periphery, a susceptor having a gear on the outer periphery, and a rotating plate having a gear on the outer periphery and transmitting a rotational driving force from the outside to the substrate holder or the susceptor. A phase growth apparatus, wherein a mark for visually detecting an amount of wear is provided at a tip of a gear of at least one rotating material selected from the substrate holder, the susceptor, and the rotating plate. This is a vapor phase growth apparatus characterized by the above.

In the vapor phase growth apparatus of the present invention, since a mark for visually detecting the wear amount is provided on the gear of at least one rotating object selected from the substrate holder, the susceptor, and the rotating plate, The amount can be easily detected by visual observation or the like, and it is possible to easily determine that the replacement time has been reached without directly measuring the amount of wear at the tip of these rotating objects.
In addition, the vapor phase growth is usually performed by storing the substrate in a container in which the source gas is circulated, and the rotating object as described above is stored and used in such a container, so that the mark can be visually recognized from the outside. By providing a viewport, the amount of wear can be easily detected without opening the reaction vessel.

The present invention includes a substrate holder having a gear on the outer periphery, a susceptor having a gear on the outer periphery, and a gas phase having a gear on the outer periphery and a rotating plate for transmitting an external rotational driving force to the substrate holder or the susceptor. Applied to growth equipment.
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. FIG. 1 is a plan view showing an example of a mark for visually detecting the amount of wear provided at the tip of a gear of a rotating object in the vapor phase growth apparatus of the present invention. It is a figure which shows the state of. FIG. 2 is a plan view showing a state in which wear of the tip end portion of the gear of FIG. 1 has progressed, and FIG. 3 is a plan view showing a state in which wear of the tip end portion of the gear of FIG. FIG. 4 is a block diagram showing an example of a substrate holder used in the vapor phase growth apparatus of the present invention. FIG. 5 is a vertical sectional view of the substrate holder shown in FIG. 4 and is a configuration diagram showing a state in which the substrate and the heat equalizing plate are installed. FIG. 6 is a configuration diagram showing an example of a susceptor used in the vapor phase growth apparatus of the present invention. FIG. 7 is a vertical sectional view showing an example of the vapor phase growth apparatus of the present invention.

  The present invention includes a substrate holder having a gear on the outer periphery, a susceptor having a gear on the outer periphery, and a gas phase having a gear on the outer periphery and a rotating plate for transmitting an external rotational driving force to the substrate holder or the susceptor. A growth apparatus, a vapor phase growth apparatus, wherein a mark for visually detecting an amount of wear is provided at a tip of a gear of at least one rotating object selected from a substrate holder, a susceptor, and a rotating plate. It is.

  For example, a mark for visually detecting the wear amount of the gear tip as shown in FIG. 1 is provided on the gear of at least one rotating object selected from the substrate holder, susceptor, and rotating plate used in the present invention. Is provided. Thus, by providing a mark at the tip of the gear that is most prone to wear, the progress of wear can be clearly detected. The marks used in the present invention are preferably provided on all the teeth constituting the gear in order to reliably detect the progress of wear, but may be provided only on some of the teeth constituting the gear.

  The mark used in the present invention is formed so as not to disappear due to contact with a high temperature or a source gas, and is preferably composed of, for example, a groove, a step, a protrusion, a pattern, a color, or a combination thereof. There is no limit. The mark used in the present invention can be formed, for example, by marking with a laser beam. Further, the mark used in the present invention may be provided with a scale indicating the length, etc., but if the mark is set corresponding to the replacement time, the gear has reached the replacement time. Can be easily determined. For example, as shown in FIG. 1, a mark is provided on the tip side from the wear position where rotation failure occurs due to wear, and as shown in FIG. 2, the time when the mark disappears due to wear is set as the replacement time. As a result, the rotating object can be replaced before the rotation failure occurs as shown in FIG. 3, so that adverse effects on the quality of the crystal film can be avoided.

  Examples of a rotating object having a gear provided with such a mark include a substrate holder as shown in FIG. 4 and a susceptor as shown in FIG. That is, the substrate holder shown in FIG. 4 is a substrate holder that can hold the substrate 6 by placing the substrate in the space portion 4, has the gear 1 on the outer periphery, and is driven by the rotational driving force transmitted through the gear 1. It is configured to be able to rotate. The susceptor shown in FIG. 6 is a susceptor that can hold a plurality of substrates by installing a substrate holder that holds the substrate in the space 9 of the susceptor, and has a gear 1 on the outer periphery. It can be rotated by the rotational driving force transmitted. As shown in FIGS. 4 and 6, a mark 2 for visually detecting the wear amount is provided at the tip of the gear of the rotating object. In addition, a mark as described above can also be provided on a rotating plate that has gears on the outer periphery and transmits external rotational driving force to the substrate holder or susceptor.

  In the vapor phase growth apparatus of the present invention, a rotating object having a gear provided with the above-described mark is usually installed inside a container in which a substrate is stored and a source gas is circulated. For example, in the vapor phase growth apparatus shown in FIG. 7, the substrate holder 3 shown in FIG. 4, the susceptor 8 shown in FIG. 6, a substrate holder rotating plate 20 having a gear on the outer periphery and transmitting a rotational driving force to the substrate holder 3, And a susceptor rotating plate 23 having a gear on the outer periphery and transmitting a rotational driving force to the susceptor 8 is provided inside the reaction vessel 27 in which the substrate is housed and the source gas is introduced from the source gas introduction part 13 to perform vapor phase growth. Is provided. In addition to the substrate holder 3 and the susceptor 8, the substrate holder rotating plate 20 and the susceptor rotating plate 23 can be provided with marks as shown in FIG.

  In the vapor phase growth apparatus of the present invention, the means for visually detecting the amount of wear at the gear tip is generally visual, but a sensor such as an optical sensor can also be used. In the vapor phase growth apparatus of the present invention, it is preferable that the above-mentioned marks can be visually recognized from the outside. For example, in the vapor phase growth apparatus shown in FIG. 7, a viewport (not shown) in which marks provided on the gears of the substrate holder 3, the susceptor 8, the substrate holder rotating plate 20, and the susceptor rotating plate 23 are visible from the outside. Can be appropriately provided at one or a plurality of locations in the reaction vessel 27.

  The rotating object as described above is placed under a high temperature accompanying the heating of the substrate and often comes into contact with a reactive source gas, and thus is composed of a material having heat resistance and corrosion resistance. For example, in a vapor phase growth apparatus in which a gallium nitride-based compound semiconductor is grown, a reactive source gas such as ammonia is circulated in addition to the substrate being heated to a high temperature (for example, 1000 ° C. or higher). Such a rotating body is composed of a material that exhibits heat resistance and corrosion resistance under such conditions, and is composed of a carbon-based material, a ceramic-based material, or a carbon-based material coated with a ceramic-based material. The gallium nitride compound semiconductor manufactured using the vapor phase growth apparatus of the present invention is a nitride semiconductor composed of a compound of one or more metals selected from gallium, indium and aluminum and nitrogen. is there.

Examples of the carbon-based material constituting the gear used in the present invention include carbon, pyrolytic graphite (PG), and glassy carbon (GC), but are not limited thereto. Examples of the ceramic material include, but are not limited to, alumina, silicon carbide (SiC), silicon nitride (Si ₃ N ₄ ), boron nitride (BN), and the like.

  Next, the vapor phase growth apparatus of FIG. 7 will be described in detail. In the vapor phase growth apparatus of FIG. 7, the vapor phase growth reaction for generating a crystal film is performed inside the reaction vessel 27. Inside the reaction vessel 27, there are a substrate 6 for vapor-phase growth of a crystal film, a substrate holder 3 for holding the substrate 6, a substrate holder rotating plate 20 for transmitting rotational driving force to the plurality of substrate holders 3, a soaking plate. 7, the heater 11 for heating the substrate 6, the plurality of substrate holders 3 and the substrate holder rotating plate 20 are rotatably held by bearing balls 24, and the susceptor 8 is rotatably held by the bearing balls 24. A ring-shaped base 26 is provided, and these members are housed in a reaction vessel 27 having a disk shape and sealed. The susceptor 8 forms a reaction furnace 12 together with the facing 10 of the susceptor, and the vapor phase growth reaction is performed in the reaction furnace 12. The substrate 6 is disposed with the growth surface on which the crystal film is grown facing downward. However, the present invention is not limited to the downward orientation. For example, the substrate may be disposed upward or laterally. Further, the present invention is not limited to the vapor phase growth apparatus that supplies the source gas from the central part of the reactor and discharges it from the peripheral part to the outside. For example, the source gas is supplied from one end of the reactor and the reaction is performed. It can also be applied to a vapor phase growth apparatus that discharges the later gas to the outside from the other end.

  The substrate holder 3 held rotatably by the susceptor 8 is rotated by receiving the rotational driving force from the substrate holder rotation driver 16. That is, the rotational driving force from the substrate holder rotation driver 16 is first transmitted to the substrate holder rotation driving shaft 17 that is rotatably sealed with respect to the reaction vessel 27 by means such as a magnetic fluid seal. The substrate holder rotation drive shaft 17 is installed in the reaction vessel 27 via a bellows or the like so that the substrate holder rotation drive shaft 17 can be moved up and down. When the claw 18 of the substrate holder rotation driving shaft 17 is inserted into the insertion port 19 of the substrate holder rotation plate 20, the rotation driving force is transmitted to the substrate holder rotation plate 20 that is rotatably held by the susceptor 8. Then, when the gear provided on the outer periphery of the substrate holder rotating plate 20 and the gear provided on the outer periphery of each substrate holder 3 are engaged with each other, the rotational driving force is transmitted to each substrate holder 3 and each substrate 6 rotates. .

  Further, the substrate 6 rotates by revolution in addition to rotation. The susceptor 8 held rotatably by the base 26 rotates by receiving a rotational driving force from the susceptor rotation driver 21. That is, the susceptor rotation drive via the susceptor rotation drive shaft 22 that is rotatably sealed so that the rotation driving force from the susceptor rotation driver 21 is freely sealed so as not to impair the sealing performance of the reaction vessel 27 by means such as a magnetic fluid seal. It is transmitted to a susceptor rotating plate 23 fixed to the tip of the shaft 22 on the susceptor side. Gears are provided on the outer periphery of the susceptor 8 and on the outer periphery of the susceptor rotating plate 23. When these gears are engaged with each other, the rotational driving force from the susceptor rotation driver 21 is transmitted to the susceptor 8, and each substrate 6 Revolves around.

  A raw material gas pipe 15 is provided at the center of the reaction furnace 12, and the raw material gas is blown out radially from the raw material gas introduction part 13 and supplied horizontally to the crystal growth surface of the substrate 6. The vapor phase growth reaction is performed by supplying the source gas from the source gas introduction unit 13 while heating the substrate 6 through the soaking plate 7 by the heater 11 in the reaction furnace 12. A crystal film is formed on the substrate. The raw material gas used for the vapor phase growth reaction is directly discharged from the reaction gas discharge unit 14 as a reaction gas.

  During vapor phase growth, the substrate 6 is preferably always rotated and revolved by the rotation of the substrate holder 3 and the susceptor 8. The rotation direction and rotation speed of the substrate holder 3 and the susceptor 8 can be arbitrarily set by changing the rotation direction and rotation speed of the substrate holder rotation driver 16 and the susceptor rotation driver 21, respectively. In order to obtain a uniform film thickness and film quality between the substrates, the substrate holders 1 are arranged on the same circumference with the source gas introduction part 13 as the center, and the distance from the source gas introduction part 13 is made equal. However, it is not limited to such a configuration.

  Although the material which comprises the reaction container 27 includes a metal or an alloy, it is not limited to these materials. The substrate holder 3, the soaking plate 7, the susceptor 8, the susceptor facing surface 10, the substrate holder rotating plate 20, and the susceptor rotating plate 23 are made of carbon-based material, ceramic-based material, or carbon-based material coated with a ceramic-based material. Although it is preferable to be configured, it is not limited to such a material. The substrate holder rotation drive shaft 17 and the susceptor rotation drive shaft 22 are preferably a metal, an alloy, a carbon-based material, a ceramic-based material, a carbon-based material coated with a ceramic-based material, or a combination thereof. There is no limit. The heater 11 is preferably a carbon heater or a ceramic heater, but is not limited to these heaters. The bearing ball 24 is preferably a ceramic material, but is not limited to a ceramic material.

Here, examples of the metal include aluminum and the like, but are not limited to aluminum, and examples of the alloy include stainless steel and Inconel, but are not limited thereto. Examples of the carbon-based material include carbon, pyrolytic graphite (PG), and glassy carbon (GC), but are not limited thereto. Examples of ceramic materials include, but are not limited to, alumina, silicon carbide (SiC), silicon nitride (Si ₃ N ₄ ), boron nitride (BN), and the like.

  The material constituting the reaction vessel 27 is particularly preferably stainless steel. Substrate holder 3, soaking plate 7, susceptor 8, susceptor facing 10, substrate holder rotating plate 20, and susceptor rotating plate 23 are SiC coated carbon, heater 11 is a carbon heater, susceptor rotation drive shaft 22 is stainless steel, bearing ball 24 is particularly preferably alumina. The substrate holder rotation drive shaft 22 is made of Inconel on the side of the substrate holder rotation drive to ensure strength, and the substrate holder rotation plate is used to prevent breakage when engaging with the substrate holder rotation plate 20. It is preferable that the side portions are made of carbon and integrated by fixing both with screws or the like.

EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not limited by this.
(Production of vapor phase growth equipment)
Inside a stainless steel reaction vessel 27, five substrate holders 3 (made of SiC-coated carbon, capable of holding one 3-inch substrate) and a disk-shaped susceptor 8 (made of SiC-coated carbon, diameter 600 mm, thickness 20 mm) , 5 substrate holders 3 can be held), susceptor facing 10 provided with a flow path 28 for circulating refrigerant (made of carbon), heater 11 (carbon heater), raw material gas inlet 13 (made of carbon), reactive gas discharge A vapor phase growth apparatus as shown in FIG. 7 was manufactured by providing a portion 14, a substrate holder rotating plate 20 (made of SiC coated carbon), a susceptor rotating plate 23 (made of SiC coated carbon), and the like. In addition, as the flow path 28 which distribute | circulates a refrigerant | coolant, one piping was arrange | positioned spirally toward the peripheral part from the center part.

  On each outer periphery of each substrate holder 3, susceptor 8, substrate holder rotating plate 20, and susceptor rotating plate 23, gears constituted by teeth protruding 6 mm in the circumferential direction were provided. A mark as shown in FIG. 1 having a width of 0.8 mm in the circumferential direction is marked with a laser beam at the tip of all teeth of each gear. In addition, each gear was meshed so that the meshing could be maintained if the amount of wear at the tip was 1 mm or less in the circumferential direction. The reaction vessel 27 was provided with a viewport (not shown) made of transparent quartz glass so that the tip of each gear could be seen from the outside.

The raw material gas introduction unit 13 forms three gas jets that are vertically partitioned by two disk-shaped partitions (made of carbon) having a diameter of 200 mm and a thickness of 2 mm. From the upper jets, ammonia and middle layers are formed. The gas containing trimethylgallium can be supplied from the nozzle and the nitrogen can be supplied from the lower nozzle. Piping was connected to each gas flow path of the source gas supply unit so that each gas having a desired flow rate and concentration could be supplied via a mass flow controller or the like.
Next, when a total of five substrates made of sapphire having a size of 3 inches were set in each substrate holder 3, the distance between the front end of the gas ejection port and the substrate was 32.4 mm.

(Vapor phase growth experiment)
Using the vapor phase growth apparatus thus manufactured, a vapor phase growth experiment was conducted in which gallium nitride (GaN) was grown on the surface of the substrate.
That is, the substrate 6 was annealed by raising the temperature of the substrate 6 to 1050 ° C. while flowing hydrogen from the source gas introduction part 13. Subsequently, the temperature of the substrate 6 is lowered to 510 ° C., and a buffer layer made of GaN is grown on the sapphire substrate 6 using trimethyl gallium and ammonia as source gases and hydrogen as a carrier gas. Then, the supply of only trimethylgallium was stopped, and the temperature of the substrate 6 was raised to 1050 ° C.

Thereafter, ammonia (flow rate: 30 L / min) from the upper jet of the raw material gas supply unit 13, trimethylgallium (flow rate: 60 cc / min) and hydrogen (flow: 30 L / min) from the middle jet, and the lower jet Was supplied with nitrogen (flow rate: 40 L / min) to grow a gallium nitride film for 2 hours. After completion of the vapor phase growth, the marks provided on the gears of each of the substrate holder 3, the susceptor 8, the substrate holder rotating plate 20, and the susceptor rotating plate 23 were visually confirmed from a viewport made of transparent quartz glass.
As a result of repeating this vapor phase growth 5 times, it was confirmed by visual observation that the gears of the substrate holder rotating plate 20 had obvious wear, and after further 5 times, the wear increased. .

  The present invention is a vapor phase growth apparatus used for growing a crystal film on a substrate, and is particularly suitable as a vapor phase growth apparatus for a gallium nitride compound semiconductor.

The top view which shows an example of the mark for detecting visually the abrasion amount provided in the front-end | tip part of the gearwheel of a rotating material in the vapor phase growth apparatus of this invention. The top view which shows the state which abrasion of the front-end | tip part of the gear of FIG. 1 advanced. FIG. 2 is a plan view showing a state where the wear of the tip of the gear of FIG. 2 has further progressed. The block diagram which shows an example of the substrate holder used for the vapor phase growth apparatus of this invention Vertical sectional view of the substrate holder shown in FIG. The block diagram which shows an example of the susceptor used for the vapor phase growth apparatus of this invention Vertical sectional view showing an example of the vapor phase growth apparatus of the present invention

DESCRIPTION OF SYMBOLS 1 Gear 2 Mark 3 Substrate holder 4 Space part 5 Substrate support part 6 Substrate 7 Soaking plate 8 Susceptor 9 Space part 10 Face of susceptor 11 Heater 12 Reactor 13 Raw material gas introduction part 14 Reactive gas discharge part 15 Raw material gas piping 16 Substrate Holder rotation drive 17 Substrate holder rotation drive shaft 18 Claw 19 Insert 20 Substrate holder rotation plate 21 Susceptor rotation drive 22 Susceptor rotation drive shaft 23 Susceptor rotation plate 24 Bearing ball 25 Bearing groove 26 Base 27 Reaction vessel 28 Refrigerant Flowing channel

Claims (5)

  A vapor phase growth apparatus comprising a substrate holder having a gear on the outer periphery, a susceptor having a gear on the outer periphery, and a rotating plate having a gear on the outer periphery and transmitting an external rotational driving force to the substrate holder or the susceptor. The tip of the gear of at least one rotating object selected from the substrate holder, the susceptor, and the rotating plate is provided with a mark for visually detecting the amount of wear. Vapor growth equipment.   2. The vapor phase growth apparatus according to claim 1, wherein the mark provided at the tip of the gear of the rotating object is set on the tip side from a wear position where rotation failure due to wear occurs.   2. The vapor phase growth apparatus according to claim 1, wherein a gallium nitride compound semiconductor is vapor-phase grown on the surface of the substrate held by the substrate holder.   2. The vapor phase growth apparatus according to claim 1, wherein the rotating object in which a mark is provided at the tip of the gear is composed of a carbon-based material, a ceramic-based material, or a carbon-based material coated with a ceramic-based material.   The vapor phase growth apparatus according to claim 1, further comprising a viewport that allows a mark provided at a tip of a rotating gear to be visually recognized from the outside.

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