JPS61268017A - Pressure reducing valve structure for semiconductor - Google Patents

Abstract

PURPOSE:To obtain the degree of vacuum on the decompressed chamber side sufficiently without using a bellows by hermetically fitting a shutoff valve into a pipe body communicated with a decompressed chamber, hermetically forming a valve partitioning a cylindrical vessel with a bottom to the vessel unified with the shutoff valve and mounting a cover to an opening section in the vessel. CONSTITUTION:An opening section in a cylindrical vessel 2 with a bottom is covered with a cover 3 and a hole 4 is formed at the central section of the cover 3, and the end of a pipe body 1, the cover 3 and the cylindrical vessel with the bottom are unified hermetically by an O ring. An annular jig 5 made of Al is screwed and fixed on the pipe body 1 side in a cover section in the periphery of the hole 4. A high pressure chamber valve 6 is shaped hermetically onto the inner wall of the cylindrical vessel 2 with the bottom through an O ring, a shutoff valve 7 is mounted hermetically into the pipe body 1, and a bar member 8 connecting the shutoff valve and the valve 6 is held hermetically by the O ring set up extending over the annular jig 5 and the hole 4. High-pressure air introducing ports 9, 10 are formed to the cylindrical vessel 2 with the bottom partitioned by the high-pressure chamber valve 6, thus completing a reducing valve structure 11 for a semiconductor.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement in a valve structure that separates a reduced pressure system and an atmospheric system essential for reduced pressure CVD, plasma CVD, etc.

[Technical background of the invention]

Although many types of semiconductor manufacturing equipment have been developed and put into practical use, a large number of them operate in a reduced pressure atmosphere.

Silicon oxide and silicon nitride are well known as surface stabilizing layers of functional elements formed in semiconductor single crystal substrates, but so-called CVD is a method for forming them.
(chemical vapor deposition) method is commonly used. One type of such methods, such as low-pressure CVD and plasma CVD, is to chemically generate silicon oxide and silicon nitride in a reaction chamber maintained in a reduced-pressure atmosphere and deposit them on a semiconductor substrate. A valve structure that controls the atmosphere is essential. Currently, this valve structure generally uses a bellows (21) as shown in FIG. That is, a pipe body (22) communicating with the depressurized chamber A is prepared, and a shutoff valve (23) is airtightly provided on its inner wall with an O-ring. A cylindrical container (24) with a bottom is prepared, and a lid (25) covering the opening thereof is airtightly provided with an O-ring (26) and connected to the end of the tube body (22). This bottomed cylindrical container (24) is provided with an air chamber valve (27) for dividing it, and a high pressure air inlet (28) (2
9). There is a hole (
30), as well as an air chamber valve (27) and a shutoff valve (2
3) is held airtight by an O-ring or the like.

There is a bellows (21) between the shutoff valve (23) and the lid (25).
is installed to constitute the valve structure, and the pipe body (22) is provided with a communication hole B to a speed reduction mechanism such as a vacuum pump. The state in Figure 2 shows the valve structure when the A side is maintained at atmospheric pressure and the B side pressure reducing mechanism is operating, and at this time high pressure air is introduced from the high pressure air introduction hole (29). The shutoff valve (23) is pressed and the inside of the tube body (22) is shut off. To reduce the pressure on the A side, introduce high pressure air from the high pressure air introduction hole (28), the air chamber valve (27) moves to the right side in the figure, and A and 8 communicate with each other to create the desired reduced pressure chamber A. Bring to a reduced pressure state.

[Problems with background technology]

As mentioned above, the bellows (
21) also expands and contracts, but its strength is weak and it was found that it would break after a relatively small number of times. Since the bellows (21) currently depend on imported products, they are very expensive, and it takes time to obtain them, resulting in a reduction in the operating rate of the device.

Originally, in this valve structure, the O-ring attached to the hole (30) of the lid (25) should prevent air from entering the bellows (21) side, but as the O-ring deteriorates, the bellows (21) side air gets mixed in. At this time, the bellows (2
If 1) fully performs its function, air will not leak to the A side, but if it is damaged as described above, it will affect the degree of pressure reduction on the A side.

[Purpose of the invention]

The present invention provides a new pressure reducing valve structure which eliminates the above-mentioned drawbacks, and which has a particularly simple structure and is intended to improve its operating efficiency.

[Summary of the invention]

In the present invention, a shutoff valve is secretly provided in the pipe communicating with the depressurized chamber, and a valve that separates the two parts is also airtightly formed in the bottomed cylindrical container that is integrated with this, and the opening of this container is The lid is arranged to airtightly integrate the tube body and the bottomed cylindrical container. A hole is formed in the center of this lid, and an annular jig is installed in the lid around this hole, facing toward the pipe body, and the stop valve and the rod member connecting the valve are held airtight together with this hole. It was made into a pressure reducing valve structure.

[Embodiments of the invention]

The present invention will be explained in detail with reference to FIG.

A pipe body ω communicating with the depressurized chamber A and a bottomed cylindrical container ■ are prepared. The opening of this bottomed cylindrical container is covered with a lid and a hole is provided in its center, and the end of the tube, the lid and the bottomed cylindrical container are airtightly integrated with an O-ring. shall be.

In the lid part around this hole), an annular jig made of Al1 is fixed by screwing it to the tube body ω side, and as a result, this is the tube body ■
The shape extends inwards.

A cylindrical container with a bottom ■A high pressure chamber valve (
0 is formed airtight, a shutoff valve ■ is airtightly installed inside the pipe body ■, and the rod member ■ that connects this shutoff valve and valve 0 is airtight with an O ring installed by hanging it over the annular jig ■ and the hole. is maintained. A high-pressure air inlet (10) is installed in a bottomed cylindrical container (2) divided by a high-pressure chamber valve (2) to complete a semiconductor pressure reducing valve structure (10). B formed in the tube body (2) is a communication hole with a pressure reducing mechanism (not shown).

In the pressure reducing valve assembly for semiconductors shown in FIG. 1, the reduced pressure chamber side is maintained at atmospheric pressure and the B side is maintained in a vacuum state. This is because high-pressure air enters the bottomed cylindrical container from the inlet (lO).
This is because the shut-off valve (■) closes off the inside of the pipe body (ω) because it is introduced into the pipe body (ω). To bring the depressurized chamber side A into a vacuum state, introduce high pressure air into the bottomed cylindrical container part from the inlet ■, move the high pressure chamber valve ■ to the left side of the drawing, and open the shutoff valve ■. A and 8 are communicated to create a vacuum state.

〔Effect of the invention〕

In this way, the half-unit decompression valve structure according to the present invention can obtain a sufficient degree of vacuum on the side of the depressurized chamber without using bellows as in the past, and uses a good-quality rose that breaks when expanded or contracted. In order to prevent leakage of high-pressure air due to pinholes, etc., it is possible to maintain the degree of vacuum in a depressurized chamber, that is, a semiconductor processing chamber by CVD, etc., at a predetermined value. Since there is almost no possibility that so-called slow leaks will occur during processing, it becomes possible to reliably perform processing essential to semiconductors.

The depressurizing valve structure according to the present invention can be managed by simply maintaining the O-ring, and unlike the case of bellows, the time and effort required for its management is not required, resulting in an improvement in the operating rate.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a pressure reducing valve structure according to the present invention, and FIG. 2 is a sectional view of a conventional valve structure.

Claims (1)

[Claims] a tube communicating with a depressurized chamber, a cylindrical container with a bottom, a lid provided at the opening of the container and airtightly connected to the end of the tube;
A hole formed in a substantially central portion of the lid, an annular jig fixed to the lid surrounding the hole and extending into the tube, a decompression mechanism communication hole provided in the tube, and a communication hole for the tube. a shutoff valve airtightly installed on the inner wall of the body; a valve airtightly installed on the inner wall of the bottomed cylindrical container to divide it; a gas inlet provided for each of the divided bottomed cylindrical containers; A pressure reducing valve structure for a semiconductor, comprising an annular jig and a rod member airtightly held in a hole and connecting the shutoff valve and the valve.