JPS6197192A - Vapor growth device - Google Patents

Abstract

PURPOSE:To obtain a vapor growth layer having high quality without causing contamination of environment and without adverse effect on bearing, etc. by preventing leakage of poisonous gas in a reaction chamber of a vapor growth device to the outside and invasion of harmful substance for the reaction into the chamber from the outside completely by sealing. CONSTITUTION:Leakage to outside of poisonous gas such as etching gas in a closed reaction chamber 3 of a vapor growth device is sealed securely for a clearance between an external periphery of a hollow shaft 4 and a base plate 1 with a first magnetic fluid seal 33 attached air-tightly with an O-ring 31, 34 to the base plate 1 side. For a space 51 between a support 5 of a susceptor, internal periphery of the hollow shaft 4, a nozzle 10, and a gas feeding pipe 9, the space is sealed securely with a second magnetic fluid 48 attached air- tightly to an O-rings 36, 44, 49 interposing a pulley 37 and a sleeve 47 attached interposing an O-ring 46. The space between the hollow shaft 4 revolving relatively to the feeding pipe 9 fixed to the base plate 1 and a fixing member 40, is sealed with magnetic fluid seals 33, 48 to prevent leakage of the gas and invasion of substances harmful for the reaction from outside.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vapor phase growth apparatus, and particularly relates to a vapor phase growth apparatus, in which a wafer support located inside a reaction chamber is driven from outside the reaction chamber via a hollow shaft, and a This relates to the driving of the hollow shaft and the sealing of the reaction chamber in a vapor phase growth apparatus that does not rotate integrally and has gas supply pipes for reactant gas, temperature sensors, and other members passed through it. be.

[Conventional technology]

As shown in FIG. 2, the vertical vapor phase growth apparatus has a reaction chamber 3 formed by a pace plate 1 and a belljar 2, and a hollow shaft 4 extending into the reaction chamber 3 through the pace plate 1. A susceptor of 6 ft is supported via a susceptor support 5. Note that 7 is a wafer and 8 is an RF coil. Inside the hollow shaft 4 is a gas supply pipe 9 for 5 reaction gases, etc.
is inserted with a gap, and a nozzle 10 is engaged with the upper end of this gas supply pipe 9 to supply a reaction gas to the surface of the wafer 7 on the susceptor.

The hollow shaft 4 is rotatably supported by a gear box 11 mounted under the base plate 1 via bearings 12.12Q, and is connected to a motor 13 provided outside the gear box 11 via a reducer 14 and gears 15.16. The lower end of the gas supply pipe 9 is fixed to a gear box 11.

By the way, since toxic gases such as reaction gas and etching gas are supplied into the reaction chamber 3, it is necessary to completely seal it from the outside air. Since the space between the gas supply pipe 9 and the gas supply pipe 9 rotates relative to each other, it is not possible to achieve a complete seal using ordinary sealing means such as an OIJ song. Therefore, conventionally, as shown in FIG. 2, an O-ring near is interposed between the base plate 1 and the gear box 11, and an O-ring 18 is interposed between the gear box 11 and the gas supply pipe 9. A magnetic fluid seal 19 is interposed in the portion of the reducer 14 and the gear 15 that penetrates the gear box 11 to seal the space between the reducer 14 and the gear 15, and the gear box communicates with the base plate 1 and the hollow shaft 4. By supplying a purge gas such as N2 gas from an inlet hole 21 to the internal space 20 of 11 and discharging it from an outlet hole 22 to a gas treatment device (not shown), toxic gases such as reaction gases are prevented from leaking into the outside air. I was doing it.

[Problem that the invention seeks to solve]

However, in such a conventional structure, wear powder is generated as the gears 15, +6 and bearings 12, 12 inside the gear box 11 rotate.

Between the base plate 1 and the hollow shaft 4 and the hollow shaft 4
and the gas supply pipe 9 into the reaction chamber 3 and cause serious defects in the vapor growth layer.
When lubricating oil was used in No. 12, there were problems such as the lubricating oil evaporating and contaminating the vapor growth layer.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention provides a structure between a member forming a reaction chamber, such as the base plate in FIG. A magnetic fluid seal is provided between each of these members, and a bearing for rotatably supporting the hollow shaft and a member for transmitting rotation to the hollow shaft are provided outside the magnetic fluid seal with respect to the reaction chamber. .

[Effect]

The reaction chamber is reliably isolated from the outside air by magnetic fluid seals between the members forming it and the hollow shaft, and between the hollow shaft and the members penetrating through it, so that toxic gases within the reaction chamber are kept away from the outside. There is no leakage to the reactor, and no external air enters the reaction chamber. The hollow shaft is supported by a bearing provided outside the magnetic fluid seal, and rotated by a rotation transmission member also provided outside. Therefore, even if there is abrasion powder from the bearing or the rotation transmission member, lubricating oil vapor, etc., there will be no adverse effect on the vapor phase growth.

〔Example〕

FIG. 1 showing one embodiment of the present invention will be described below.

1 is a base plate, 4 is a hollow shaft, 5 is a susceptor support,
Reference numeral 9 represents a gas supply pipe, and reference numeral 10 represents a nozzle, which are substantially the same as each member shown using the same reference numerals in FIG.

Reference numeral 30 designates a first magnetic fluid sealed bearing, into which the hollow shaft 4 is fitted and is fixed to the lower surface of the base plate 1 with a bolt 32 with a ring 31 interposed therebetween. A first magnetic fluid seal 33 is disposed within the first magnetic fluid seal bearing 30 and rotatably seals the outer periphery of the hollow shaft 4 . Note that the distance between the housing 30a of the first magnetic fluid seal bearing 30 and the first magnetic fluid seal 33 is zero.
+) Sealed by y-g 34.

The hollow shaft 4 is rotatably attached to the inner housing 30a through bearings 35, 35. These bearings 35.35
In FIG.
The magnetic fluid seal 33 is disposed below the magnetic fluid seal 33 . A pulley 37 is connected to the lower end of the hollow shaft 4 with a QIJ ring 36 interposed therebetween.
is attached with a bolt 38, and is configured to be rotated by a motor (not shown) via a belt 39.

The gas supply pipe 9 is located at the center of the hollow shaft 4, and its lower end side extends further downward than the pulley 37, and is fixed to a fixing member 40 such as a frame by a pressing piece 41 and a bolt 42. A gas supply pipe 9 is provided on the lower surface of the pulley 37.
A second magnetic fluid sealed bearing 43 into which the gas supply pipe 9 is fitted is attached by a bolt 45 with a 01J ring 44''f interposed therebetween. The structure formed by, etc.
A sleeve 47t formed of a magnetic material is fitted onto this gas supply pipe 9 with an OIJ song 6 interposed therebetween.
7 has a second ferrofluidic seal 48 acting on the outer periphery of 7. In addition, 49 is an O-ring, and 50.50 is a bearing. These bearings 50, 50υ, like the bearings 35, 35 of the first ferrofluid seal bearing 30, are located below the second ferrofluid seal 48 (in FIG. It is located so that it is located at In addition, these bearings 50, 50fl
This is for reliably and stably positioning the gas supply pipe 9 and the sleeve 47 at the center of the second magnetic fluid seal 48, and since the gas supply pipe 9 is fixed to the fixing member 40, it is not necessarily necessary. isn't it.

Next, the operation of this device will be explained. The gas in the reaction chamber 3 tries to leak out from between the outer periphery of the hollow shaft 4 and the base plate 1, but the O-ring 31.
Since the gas is securely sealed by the first magnetic fluid seal 33 which is airtightly attached to the base plate 1 side by 34, there is no leakage of the gas, and outside air enters the reaction chamber 3 through this gap. There's nothing to do.

The gas in the reaction chamber 3 is supplied to the susceptor support 5 and the hollow shaft 4 that follows it, and the nozzle 10 and the gas supply pipe 9 that follows it.
However, the space 5I between these leaks through the O-ring 36.44.4 via the pulley 37.
9, the second magnetic fluid seal 48 is airtightly attached to the hollow shaft 4, and the space is attached to the gas supply pipe 9 via an O-ring 46 and securely sealed by a sleeve 47 Gas leakage through the entire reaction chamber 51 is also reliably prevented, and outside air does not enter into the reaction chamber 3 through this gap.

The gas supply pipe 9 is fixed to a fixed member 40 and does not rotate, and the hollow shaft 4 is rotated by a motor (not shown) via a plate 3'I, a pulley 37, etc. Therefore, the hollow shaft 4 rotates relative to the base plate and the gas supply pipe 9, and since the first and second magnetic fluid seals 33, 48 are provided between them, The rotation is not inhibited, and reliable sealing is performed even during the rotation.

Since the rotation transmission members such as the bearings 35, 35, 50, 50, pulley 372, and belt 39 are separated by the first and second magnetic fluid seals 33 and A8 and are located outside the reaction chamber 3, Abrasion powder is generated from these, and even if the lubricating oil supplied to the bearings 35, 35, 50, 5o evaporates, these will not enter the reaction chamber 3, and furthermore, reaction gas and etching gas is bearing 35.35.50,5
0, the pulley 37, belt 39, etc. will not be touched and have no adverse effect on them.

Although not shown in the drawings, the base plate 1 is normally cooled by cooling water flowing therein, but there is also a rotary joint roller (not shown) inside the portion of the hollow shaft 4 that faces the first magnetic fluid seal 33. It is preferable to cool the hollow shaft 4 by flowing cooling water to keep the first magnetic fluid seal 33, which is easily heated, at a lower temperature.

The above-mentioned embodiment is one in which the present invention is applied to a hollow shaft 4 for rotating a susceptor of a vertical vapor phase growth apparatus and a gas supply pipe 9 passing through the hollow shaft 4.
Although all examples have been shown, the present invention is not limited to this, and the present invention is applicable to relative rotation, such as a hollow shaft for rotating a susceptor of a barrel-type vapor phase growth apparatus and a temperature sensor passing through the hollow shaft. It goes without saying that the present invention can be applied as is to double-structured parts that produce. [L In the above-mentioned embodiment 7'c, the first and second magnetic fluid seals 33 and 48 are provided offset in the axial direction. Various changes may be made, such as:

〔Effect of the invention〕

As described above, according to the present invention, the seal of the double structure part consisting of a hollow shaft and a member such as a gas supply pipe that passes through the hollow shaft and does not rotate integrally with the hollow shaft completely inhibits the rotation of the hollow shaft. In addition, bearings and rotation transmission members that generate abrasion particles and lubricating oil vapor that adversely affect vapor phase growth are located outside the reaction chamber separated by a magnetic fluid seal. Contamination can be more reliably prevented and a high-quality vapor-grown layer can be obtained, and additionally, reaction gases and etching gases do not have an adverse effect on bearings.

[Brief explanation of drawings]

Fig. 1 is an enlarged sectional view of main parts showing one embodiment of the present invention;
The figure is a schematic cross-sectional view showing an example of a conventional vertical vapor phase growth apparatus. 1...Pace plate, 2...Beljar, 3.
...Reaction chamber, 4...Hollow shaft. 5...Susceptor support, 6...Susceptor, 7...
・Wafer, 8...RF coil, 9...Gas supply pipe% 1o...Nozzle, +2.35.50...Bearing, 15.16...Gear, +9...Magnetic fluid seal,

Claims (1)

[Scope of Claims] 1. The wafer support located inside the reaction chamber is rotated via a hollow shaft by a drive unit provided outside the reaction chamber, and the wafer support extends from outside the reaction chamber into the reaction chamber by passing through the hollow shaft. In a vapor phase growth apparatus having a member that does not rotate integrally with the hollow shaft, there is a magnetic field between the member forming the reaction chamber and the hollow shaft, and between the hollow shaft and a member passing through the hollow shaft. A vapor phase growth apparatus characterized in that a fluid seal is provided, and a bearing that rotatably supports the hollow shaft and a rotation transmission member to the hollow shaft are provided outside the magnetic fluid seal with respect to the reaction chamber. 2. Claim 1, characterized in that the respective magnetic fluid seals are arranged with positions shifted in the axial direction.
Vapor phase growth apparatus described in Section 1. 3. The vapor phase growth apparatus according to claim 1, wherein each of the magnetic fluid seals is disposed at the same position in the axial direction, overlapping each other.