JP3345840B2 - Operating method of self-revolution type vapor phase growth apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-revolving type vapor phase growth apparatus for revolving a susceptor in a reactor and rotating a tray supported by the susceptor to perform vapor phase growth on a wafer on the tray. It is related to the driving method.

[0002]

2. Description of the Related Art A wafer is supported on a susceptor in a reactor, and while the susceptor is heated to a high temperature (eg, about 700 ° C.), AsH ₃ (arsine), TMG
An epitaxial wafer formed by flowing a source gas such as (trimethylgallium) and TMAl (trimethylaluminum) together with a carrier gas composed of hydrogen and epitaxially growing the wafer is used as a material for FETs and HEMT devices for satellite broadcasting, mobile phones, and the like. It is used as

This epitaxial wafer is manufactured by mounting a wafer on each surface of a polygonal barrel type susceptor. The variation in the film thickness of the epitaxial wafer is preferably as low as possible, but was about ± 5% in a normal apparatus.

[0004] Recently, the demand for higher yield and higher quality in the post-process requires a variation in the thickness of the epitaxial wafer of ± 2% or less.

In view of the above, there has been proposed a rotation-revolution type gas phase growth apparatus in which a rotation tray is provided on each surface of a polygonal barrel type susceptor and the rotation tray rotates while rotating the susceptor, thereby improving the uniformity of the film thickness. Have been.

In this self-revolving type vapor phase epitaxy apparatus, a barrel type susceptor is provided in a reactor, and a lower chamber having an open lower portion is provided in the susceptor, and the susceptor is formed by a susceptor revolving shaft oriented vertically. The revolving tray is rotatably supported on the surface of the susceptor, and the tray rotating shaft for rotating the revolving tray is rotatably penetrated through the susceptor and is led out into the lower chamber. A tray rotating planetary gear is supported on the derived tray rotating shaft, and a gear stand is arranged below the susceptor on the outer periphery of the susceptor revolving shaft via a bearing. It has a structure in which a fixed ring gear that is coaxial and meshes with the tray rotating planetary gear is provided.

[0007]

However, in such a conventional spin-revolution type vapor phase growth apparatus, an excessive force acts on the gear mechanism during operation at a high temperature, so that not only the gears and the like are damaged, but also In the worst case, there has been a problem that a damaged component hits a glass reactor to break the reactor or leak harmful gas.

[0008] Therefore, securing safety during operation of the self-revolution type vapor phase growth apparatus has become a major problem.

It is an object of the present invention to provide a method of operating a self-revolution type vapor phase growth apparatus which can ensure safety during operation.

[0010]

As a result of various investigations by the present inventors, the following has been found.

(A) As shown in FIG. 1, when the temperature of the susceptor and the tray rises, the frictional force acting on the gear mechanism decreases, but when the temperature decreases, the frictional force sharply increases.

(B) As shown in FIG. 2, when the pressure in the reactor is reduced, the frictional force acting on the gear mechanism increases from that at normal pressure.

The means of the present invention for achieving the above object in consideration of the cause of the frictional force acting on such a gear mechanism will be described as follows.

According to the first aspect of the present invention, a susceptor is provided in a reactor, the susceptor is supported by a vertically oriented susceptor revolving shaft, and a rotation tray is rotatably supported on a surface of the susceptor. A tray rotating shaft that rotates the rotation tray is rotatably penetrated through the susceptor and is led out to the back side. A gear stand is arranged on the outer periphery of the susceptor revolving shaft below the susceptor, and a back side of the susceptor is provided. A self-revolving type vapor phase growth apparatus provided with a gear mechanism for rotating the tray rotation shaft using the rotation of the susceptor is provided between the tray rotation shaft and the gear stand. In the operation method of the revolution type vapor phase growth apparatus, the gear stand is fixed when the tray rotates, and when the temperature of the susceptor and the tray is lowered or the reactor is cooled. The decompression time, characterized in that the free the gear stand.

According to a second aspect of the present invention, a susceptor is provided in a reactor, the susceptor is supported by a vertically oriented susceptor revolving shaft, and a rotation tray is rotatably supported on a surface of the susceptor. A tray rotating shaft for rotating the rotation tray is rotatably penetrated through the susceptor and is led out to the back side, and a gear stand is arranged on an outer periphery of the susceptor revolving shaft below the susceptor, and a back side of the susceptor is provided. A self-revolving type vapor phase growth apparatus provided with a gear mechanism for rotating the tray rotation shaft using the rotation of the susceptor is provided between the tray rotation shaft and the gear stand. In the method for operating a revolution type vapor phase growth apparatus, the gear may be rotated when the tray rotates.
Fix the stand and cool down the susceptor and tray
The gear stand should be closed when
And Lee, lowering of the susceptor and said tray, said
With the gear stand free , cool down, cool down,
It is characterized in that the temperature is lowered and the temperature is stopped in a stepwise manner.

[0016]

According to the first aspect of the invention, when the gear stand is set free when the temperature of the susceptor and the tray is lowered or the pressure in the reactor is reduced, the gear stand rotates together with the rotation of the susceptor, and the gear mechanism is driven. No excessive force is applied to the gear mechanism when the temperature of the susceptor and tray is lowered or the pressure in the reactor is reduced.
This can prevent the reactor from being damaged. Therefore, safety during operation of the self-revolution type vapor phase growth apparatus when the temperature of the susceptor and the tray is lowered or when the pressure in the reactor is reduced can be secured.

According to a second aspect of the present invention, when the temperature of the susceptor and the tray is lowered in a step-like manner by repeatedly lowering the temperature, stopping the temperature lowering, and lowering the temperature while the gear stand is kept free , the susceptor and the tray are lowered. When the temperature is lowered, no excessive force acts on the gear mechanism, and damage to the gears and the like and associated damage to the reactor can be prevented. Therefore, safety during operation of the self-revolving type vapor phase growth apparatus when the temperature of the susceptor and the tray is lowered can be secured.

[0018]

FIG. 3 shows an embodiment of a self-revolution type vapor phase growth apparatus for implementing the method of operating the self-revolution type vapor phase growth apparatus according to the present invention.

In this self-revolution type vapor phase growth apparatus, a barrel type susceptor 2 made of carbon or the like is provided in a reactor 1 made of quartz glass or the like. The susceptor 2 is provided with a lower chamber 3 whose lower part is opened.
The susceptor 2 is supported by a vertically oriented susceptor revolving shaft 4 so as to revolve freely. The susceptor revolving shaft 4 is divided into a susceptor holder shaft 4a made of quartz glass or the like and a drive shaft 4b made of stainless steel or the like, which are separably connected. A locking projection 6 is provided on the upper part of the susceptor holder shaft 4a so as to be engaged with the locking hole 5 of the susceptor 2 so that the rotational force of the susceptor revolution shaft 4 can be given to the susceptor 2. Also, susceptor 2
Is moved up and down by elevating the susceptor revolution shaft 4.

A recess 7 is provided on the surface of the susceptor 2.
A tray 8 made of carbon or the like is rotatably fitted into and supported by the recess 7. The tray 8 is fitted into the recess 7 so that the surface of the wafer 9 supported on the surface thereof matches the surface of the susceptor 2. Tray 8
Is rotatably penetrated through the susceptor 2 and is led out into the lower chamber 3 on the back surface of the susceptor 2.

A tray rotating planetary gear 11 made of quartz glass or the like is fixed to a tray rotating shaft 10 led into the lower chamber 3 on the back surface of the susceptor 2. A cylindrical gear stand 13 made of quartz glass or the like is disposed below the susceptor 2 on the outer periphery of the susceptor revolution shaft 4 via a bearing 12. A skirt portion 13a for closing the lower chamber 3 of the susceptor 2 and preventing gas turbulence at the lower portion of the susceptor 2 is provided on the outer periphery of the gear stand 13. A fixed ring gear 14 made of carbon or the like, which is coaxial with the susceptor revolving shaft 4 and meshes with the tray rotating planetary gear 11, is provided above the gear stand 13. The fixed ring gear 14 and the tray rotating planetary gear 11 constitute a gear mechanism 15 for rotating the tray rotating shaft 10 using the rotation of the susceptor 2.

The gear stand 13 is fixed to the reactor 1 by an operating tool 17 such as an electromagnetic solenoid having a lock pin 16.

The part of the reactor 1 below the susceptor 2
An exhaust section 18 and an exhaust pipe 19 are provided. A high-frequency heating coil 20 as a heater for heating the susceptor 2 is arranged on the outer periphery of the reactor 1. A gas inlet 21 is provided in an upper part of the reactor 1. Reactor 1
Is closed with the susceptor revolution shaft 4 rotatably penetrating therethrough.

Next, a description will be given of a first embodiment of an operation method using such a self-revolution type vapor phase growth apparatus. In the self-revolution type vapor phase growth apparatus, the heating coil 20 rotates the susceptor 2 while rotating the susceptor 2 by the rotation of the susceptor revolution shaft 4.
Is heated, and the wafer 9 is heated. In this state, a source gas and a carrier gas are introduced into the reactor 1 from the gas inlet 21 to cause the wafer 9 to undergo vapor phase growth. At this time, as the susceptor 2 revolves, the tray rotating planetary gear 11 meshes with the fixed ring gear 14 and rotates while revolving. Along with this, the tray 8 supporting the wafer 9 on its surface is also rotated while rotating. Therefore, vapor phase growth having substantially the same film thickness can be performed at each part of the wafer 9.

When the temperature of the susceptor 2 and the tray 8 is lowered during such a vapor phase growth operation, the lock pin 16 is pulled by operating the operating tool 17 to make the gear stand 13 free.

Thus, when the susceptor 2 is rotated, the gear stand 13 is also rotated together with the gear mechanism 15 so that the gear mechanism 15 is not driven. Therefore, when the temperature of the susceptor 2 and the tray 8 is lowered, an excessive force is applied to the gear mechanism 15. No longer works, and damage to the gears 11, 14 and the like and accompanying damage to the reactor 1 can be prevented. Therefore, the susceptor 2 and the tray 8
When the temperature is lowered, safety during operation of the self-revolution type vapor phase growth apparatus can be ensured.

For example, as shown in FIG. 4, when performing vapor phase growth in which the temperature is changed with time, the lock pin 16 is used.
The gear stand 13 is fixed to rotate the tray 8 while revolving, and a process is performed at 700 ° C. for a predetermined time. At a point indicated by a point A in FIG. Then, the rotation of the tray 8 is stopped and the temperature is lowered. At the point indicated by a point P 'at which the temperature reaches 500 ° C., this temperature is held for a predetermined time, and the temperature is lowered.
The lock pin 1 is operated by operating the operating tool 17 at a point indicated by a point P after a lapse of a predetermined time from a point indicated by a point P 'when the temperature reaches 500 ° C.
6, the gear stand 13 is fixed, the tray 8 is revolved and re-rotated, and the raw material gas flows into the reactor 1 from the point indicated by the point P. The period from the time point A to the time point P is the epitaxy stop time. After a predetermined time from the point P, the temperature is raised again,
When the temperature reaches 700 ° C, the temperature is maintained for a predetermined time.

When the pressure in the reactor 1 is reduced (several tens of Torr)
Since the frictional force acting on the gear mechanism 15 is increased also in (2), the lock pin 16 is pulled by operating the operating tool 17, the gear stand 13 is set free, and the rotation of the tray 8 is stopped. In this manner, safety during operation of the self-revolving type vapor phase growth apparatus when the pressure in the reactor 1 is reduced can be ensured.

The gear stand 13 is locked by the lock pin 16, for example, by providing a hole or a groove at a predetermined position of the gear stand 13, and detecting the positions thereof by a rotational position detecting means provided below the susceptor revolution shaft 4. Detection is performed by inserting the lock pin 16 into the hole or groove of the gear stand 13.

When performing vacuum baking inside the reactor 1,
The susceptor 2 is heated to 800 ° C. or more and revolved to stabilize the temperature. Also in this case, if the lock pin 16 is not removed, the device will be damaged.

Next, a description will be given of a second embodiment of the operation method using such a self-revolution type vapor phase growth apparatus. In this embodiment, when the temperature of the susceptor 2 and the tray 8 decreases, the lock pin
The gear stand 13 is free by pulling the gear 16
Then, the temperature is decreased stepwise by repeating the steps of decreasing the temperature, stopping the cooling, stopping the temperature, and stopping the cooling.

In this manner, when the temperature of the susceptor 2 and the tray 8 is lowered, no excessive force acts on the gear mechanism 15, and damage to the gears 11, 14 and the like, and damage to the reactor 1 associated therewith can be prevented. Therefore, the susceptor 2 and the tray 8
The safety during operation of the self-revolution type vapor phase growth apparatus when the temperature is lowered can be ensured.

For example, as shown in FIG. 5, when performing vapor phase growth in which the temperature is changed with time, the lock pin 16 is used.
In performing a predetermined time processing at 700 ° C. by rotating while revolving the tray 8 by fixing the gear stand 13, then Rokkupi
The gear stand 13 free pulling the emission 16, and the temperature is lowered to the point indicated by point B at the time indicated by point A shown t ₁ ° C.
(For example, 690 ° C.). Here, control is performed at the same temperature for several minutes. Next, at the time point indicated by the point C, the temperature is lowered to the time point indicated by the point D to reach t ₂ ° C (for example, 680 ° C). Here, control is performed at the same temperature for several minutes. In this way, the temperature is reduced step by step by repeating the steps of cooling down, cooling down, cooling down, and cooling down.

[0034]

As described above, according to the method of operating the self-revolution type vapor phase growth apparatus according to the present invention, the following effects can be obtained.

In the operation method of the present invention, the gear stand is free when the temperature of the susceptor and the tray is lowered or when the pressure inside the reactor is reduced. The gear mechanism will not be driven due to the rotation of the gear, so that excessive force will not act on the gear mechanism when the temperature of the susceptor and tray is lowered or the pressure inside the reactor is reduced, preventing damage to gears and the like, and damage to the reactor as a result. it can. Therefore, it is possible to ensure safety during operation of the self-revolving type vapor phase growth apparatus when the temperature of the susceptor and the tray is lowered or when the pressure in the reactor is reduced.

In the operation method of the rotation -revolution type vapor phase growth apparatus according to the second aspect, the gear stand is fixed when the tray rotates.
When the temperature of the susceptor and tray is lowered or the pressure inside the reactor is reduced
The gear stand is set free, and the temperature of the susceptor and the tray is lowered.In a state where the gear stand is set free, the temperature is lowered, the temperature is stopped, the temperature is lowered, and the temperature is stopped. Unreasonable force does not act on the mechanism, which can prevent damage to gears and the like and associated damage to the reactor. Therefore, it is possible to ensure safety during operation of the self-revolution type vapor phase growth apparatus when the temperature of the susceptor and the tray is lowered.

[Brief description of the drawings]

FIG. 1 is a diagram showing a frictional force acting on a gear mechanism when the temperature of a susceptor and a tray rises and falls.

FIG. 2 is a diagram showing a frictional force acting on a gear mechanism at the time of pressure reduction in a reactor.

FIG. 3 is a longitudinal sectional view of an embodiment of an apparatus for performing a method of operating a self-revolution type vapor phase growth apparatus according to the present invention.

FIG. 4 is a diagram showing a temperature control state in an embodiment of the method of operating the self-revolution type vapor phase growth apparatus according to the present invention.

FIG. 5 is a diagram showing a temperature control state in another embodiment of the method of operating the self-revolution type vapor phase growth apparatus according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reactor 2 Susceptor 3 Lower chamber 4 Susceptor revolving shaft 4a Susceptor holder shaft 4b Drive shaft 5 Locking hole 6 Locking protrusion 7 Recess 8 Tray 9 Wafer 10 Tray rotating shaft 11 Tray rotating planetary gear 12 Bearing 13 Gear stand 13a Skirt portion 14 Fixed ring gear 15 Gear mechanism 16 Lock pin 17 Operating tool 18 Exhaust unit 19 Exhaust pipe 20 High frequency heating coil 21 Gas inlet

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-60-27120 (JP, A) JP-A-1-196119 (JP, A) JP-A-3-85724 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) H01L 21/205

Claims (2)

(57) [Claims] 1. A susceptor is provided in a reactor, the susceptor is revolvably supported by a vertically oriented susceptor revolving shaft, and a rotation tray is rotatably supported on the surface of the susceptor, and rotates the rotation tray. The tray rotation shaft is rotatably penetrated through the susceptor and is led out to the back side, a gear stand is arranged below the susceptor on the outer periphery of the susceptor revolution shaft, and the tray rotation led out to the back side of the susceptor. A self-revolution type vapor phase growth apparatus that operates a self-revolution type vapor phase growth apparatus provided with a gear mechanism for rotating the tray rotation axis by using the rotation of the susceptor between a shaft and the gear stand. In the operating method, the gear stand is fixed when the tray rotates, and the gear is fixed when the temperature of the susceptor and the tray is lowered or when the pressure in the reactor is reduced. How the operation of the revolving type vapor deposition apparatus characterized by the stand free. 2. A susceptor is provided in a reactor, the susceptor is revolvably supported by a vertically oriented susceptor revolving shaft, and a rotation tray is rotatably supported on a surface of the susceptor, and rotates the rotation tray. The tray rotation shaft is rotatably penetrated through the susceptor and is led out to the back side, a gear stand is arranged below the susceptor on the outer periphery of the susceptor revolution shaft, and the tray rotation led out to the back side of the susceptor. A self-revolution type vapor phase growth apparatus that operates a self-revolution type vapor phase growth apparatus provided with a gear mechanism for rotating the tray rotation axis by using the rotation of the susceptor between a shaft and the gear stand. In the driving method, the gear stand is fixed when the tray rotates, and
When the temperature of the susceptor and the tray is lowered,
Vacuum at the time of the free the gear stand, the cooling of the susceptor and said tray, said gear Stan
The method of operating a self-revolving type vapor phase growth apparatus, wherein temperature reduction, temperature reduction stop, temperature reduction, and temperature reduction stop are repeatedly performed in a step-like manner with the metal free .