JPS6214223B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a vapor phase growth apparatus, and particularly to the structure of a rotation drive section of a wafer support located within a reaction chamber.

[Conventional technology]

As shown in FIG. 2, in a barrel-type vapor phase growth apparatus, a wafer support 3 such as a susceptor supported by a rotating shaft 2 is positioned inside a vertically arranged reaction tube 1, and the outside of the reaction tube 1 is A heating source 4 such as an RF coil (hereinafter referred to as RF coil) installed in the wafer support 3 generates heat to heat the wafer 5 set on the surface of the wafer support 3, and reactant gas is supplied from the nozzle 6 to heat the wafer 5. A vapor phase growth layer is formed on the surface. The wafer support 3 is connected to a motor 7, a gear 8,
9, 10, 11 and the rotating shaft 2, and conventionally, the rotating shaft 2
was formed into a hollow shaft through which a temperature sensor 12 penetrated to detect the temperature of the wafer support 3. By the way, a reaction gas or Since toxic gas such as etching gas is supplied, it is necessary to seal the reaction chamber 17 airtight from the outside.
Since it is hollow and the temperature sensor 12 passes through it, it is impossible to seal this part of the rotating shaft 2. Therefore, as shown in FIG. A cover 19 is provided that covers the outer end and the gears 10, 11, and a magnetic fluid seal 20 is provided between the gear 9 and the gear 10 that passes through the cover 19 to transmit rotation from the outside to the inside. The base end of the sensor 12 and the cover 19
A seal 21 is provided between the cover 19 and the space 22 to make the space 22 inside the cover 19 airtight. It was designed to prevent leaks. Note that 23 is a page gas introduction pipe.

[Problem that the invention seeks to solve]

However, in such a conventional structure, abrasion powder generated as the gears 10 and 11 in the cover 19 and the bearing 24 of the rotating shaft 2 rotate enters the reaction chamber 17 and causes vapor phase growth. In addition, when lubricating oil was used for the bearing 24, etc., there were problems such as evaporation and contamination of the vapor growth layer.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention has improved the dual structure consisting of a hollow rotating shaft and a temperature sensor that penetrates the hollow rotating shaft, which was an obstacle to sealing, and has replaced the rotating shaft that connects the wafer support. A solid shaft is used, a magnetic fluid seal is provided between the rotating shaft and the member forming the reaction chamber, and the bearing of the rotating shaft is placed outside the reaction chamber partitioned by the magnetic fluid seal. It is something.

[Effect]

The rotating shaft according to the present invention and the wafer support connected thereto are rotatably supported by the bearing in the same manner as in the conventional apparatus. However, since this bearing is located outside the reaction chamber that is reliably partitioned by a magnetic fluid seal, wear particles and lubricating oil vapor do not enter the reaction chamber. Furthermore, the temperature of the wafer support and the wafer is measured by providing a temperature sensor such as an infrared temperature detector outside the reaction tube.

〔Example〕

FIG. 1 showing one embodiment of the present invention will be described below. 1 is a reaction tube, 3 is a wafer support, 4 is a
The RF coil and 5 are wafers, which are similar to the conventional device shown in FIG. In FIG. 1, the reaction tube 1 is covered with a lid 31 which can be opened and closed via a seal 30 at its upper end, and a plurality of nozzles 32 are attached to the lid 31. A shaft 33 is provided in the upper center of the wafer support 3, and a coupling 34 is provided.
A rotating shaft 35 is connected via. This rotating shaft 35 is a solid shaft. 36 is a magnetic fluid seal, which is usually sold as a pair with the rotating shaft 35 on the market. This magnetic fluid seal 36 is attached to the lid 31 via a seal 37. Rotating shaft 35
is rotatably supported by the lid 31 by a bearing 38 located above the magnetic fluid seal 36 in FIG. A gear 39 is attached to the upper end of the rotating shaft 35, and rotation is applied by a motor 41 via a gear 40. In addition, 4
Temperature sensors 2 and 42 detect the temperature of the wafer 5 through the reaction tube 1 between the RF coils 4.

Next, the operation of this device will be explained. The wafer support 3 includes a shaft 33, a coupling 34, and a rotating shaft 3.
5. Since it is rotatably supported by the lid 31 via the bearing 38, the gears 40, 3 are driven by the motor 41.
9, it is rotationally driven in the same way as in the conventional case. In the part of the lid 31 through which the rotating shaft 35 passes, the lid 31 and the magnetic fluid seal 36 are reliably and airtightly partitioned by a seal 37, and the area around the rotating shaft 35 is securely partitioned by the magnetic fluid seal 36. It is airtightly partitioned. Therefore, the reaction chamber 43 formed by the reaction tube 1 and the lid 31 is reliably made airtight to the outside, and the reaction gas supplied from the nozzle 32 does not leak to the outside. Moreover, on the contrary, outside air does not enter into the reaction chamber 43 from around the rotating shaft 35, and therefore the bearing 38 and the gear 3
Even if abrasion powder is generated from 9, 40, etc., it does not have any adverse effect on vapor phase growth, and lubricating oil can also be freely used.

Note that the lid 31 is provided with a cooling fluid flow path (not shown), and the lid 31 itself and the magnetic fluid seal 3
6. It is preferable to keep the bearing 38, seals 30, 37, etc. as low as possible, and furthermore, the rotating shaft 35
A flow path is also provided inside the rotary shaft 3 by circulating the cooling fluid through the rotary joint 44.
Preferably, the ferrofluidic seal 36 is protected by preventing temperature rise of the ferrofluidic seal 36.

〔Effect of the invention〕

As described above, according to the present invention, a reliable seal can be established between the rotating shaft that connects the wafer support and the members forming the reaction chamber, and rotation transmission members such as bearings and gears are separated from the reaction chamber. Since it is located in a completely separated area, future wear debris and lubricating oil vapor will not have a negative effect on vapor phase growth, as is clear from comparing Figures 1 and 2. Effects such as easy structure can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view showing an embodiment of the present invention;
FIG. 2 is a schematic sectional view of a conventional device. 1...Reaction tube, 3...Wafer support, 4...
RF coil, 5... Wafer, 30, 37... Seal, 31... Lid, 35... Rotating shaft, 36... Magnetic fluid seal, 38... Bearing, 39, 40... Gear, 41... Motor, 42, 42...Temperature sensor, 43...Reaction chamber, 44...Rotary joint.

Claims (1)

[Claims] 1 In a vapor phase growth apparatus in which a wafer support located inside a reaction chamber is rotated by a drive unit provided outside the reaction chamber, the rotation shaft connected to the wafer support is a solid shaft, and the reaction with the rotation shaft is A vapor phase growth apparatus characterized in that a magnetic fluid seal is provided between a member forming a chamber, and a bearing rotatably supporting the rotating shaft is disposed outside the magnetic fluid seal with respect to the reaction chamber.