JPH03206376A - Evacuation device - Google Patents

Abstract

PURPOSE:To adjust to obtain desired process pressure without lowering of the evacuating speed against water by arranging a cryotrap on the vacuum tank side, and also arranging a conductance control valve between the cryotrap and a vacuum pump. CONSTITUTION:In an evacuating passes connecting a sputter device 1 as a vacuum tank to a cryopump 5 as a vacuum pump, a cryotrap 3 is arranged on the sputter device 1 side and a conductance control valve 4 is arranged between the cryotrap 3 and the cryopump 5. Hereby, because the cryotrap 3 is positioned on the preceding stage of the conductance control valve 4, resistance for gas flow is small and evacuating speed against water can be heightened. Consequently, adjustment to obtain desired process pressure can be performed without lowering of the evacuating speed against water, and a process atmosphere of good quality can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vacuum evacuation device that evacuates a vacuum chamber using a vacuum pump.

[Conventional technology and its problems]

For example, a conventional vacuum evacuation device used when evacuation of a vacuum chamber such as a sputtering device using a cryopump is shown in FIGS. 2 and 3.

FIG. 2 shows an example in which a cryopump (6) with a cryotrap is attached to a vacuum chamber (1) via a vacuum valve (2) and a conductance valve (4) that controls conductance, that is, displacement. Also, Figure 3 shows the vacuum chamber (
1) Vacuum valve (7) with conductance control function
) via cryopump with cryotrap (6)
This is an example of installing the .

Here, a cryopump with a cryotrap set up or integrated on the intake side of a cryopump is referred to as a cryopump with a cryopump.

A vacuum chamber [1
) When exhausting the residual moisture in the sputtering equipment using a cryotrap and adjusting the pressure inside the spatter equipment to the desired process pressure, the conductance valve (4) is used in the example shown in Figure 2. ) was performed by adjusting the vacuum valve (7) with a conductance control function in the example shown in FIG.

For example, the fifth valve controls the conductance.
Conductance valve (butterfly type) shown in figure A (19
) and variable rifice (sair riffice type) in Figure 5B.
(15) etc. Conductance valve (l9)
When using the valve body (l3), the valve body (l3) is provided in the middle of the exhaust path, and the conductance is adjusted by adjusting the rotation angle of the valve plate (l4) using the driving part (l2). In addition, in the case of barrier pull orifice (15), the valve body (1
7) is provided in the middle of the exhaust path, and the drive unit (16) adjusts the rotation angle of the plurality of orifice plates (l8) to open and close the passage (20) between the orifice plates (18) to adjust the conductance. .

When forming a film by sputtering, moisture remaining in the sputtering equipment can be a problem, so it is necessary to remove as much moisture as possible. Since the conductance is controlled on the vacuum chamber side of the trap-equipped cryopump, there is a problem in that when the conductance is reduced, the process gas (argon) exhaust speed becomes smaller, and at the same time, the water pumping speed also becomes smaller.

[Problem that the invention seeks to solve]

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a vacuum evacuation device that can adjust the pressure within a vacuum chamber without reducing the pumping speed for water.

[Means for solving the problem] The above object is to provide a cryotrap on the vacuum chamber side in an exhaust path connecting a vacuum chamber and a vacuum pump, and to provide a cryotrap between the cryotrap and the vacuum pump. This is achieved by a vacuum evacuation device characterized in that it is equipped with a conductance control valve.

[Function] In the vacuum evacuation device configured as described above, the cryotrap and cryopump are separated, and the cryotrap is installed closer to the vacuum chamber than the cryopump and the conductance control valve, so that the evacuation of water is prevented. It becomes possible to adjust the desired process pressure without reducing speed.

[Example] Next, embodiments will be described with reference to the drawings.

FIG. 1 shows an example of the present invention, in which (l) is a sputtering device that is a vacuum chamber, (2) is a vacuum valve, (3) is a cryotrap, (4) is a conductance control valve, and (5) is a It is a cryopump.

Here, the cryotrap (3) has the structure shown in Figures 4A and 4B, and a helium refrigerator (9) and 80K cryopanels (10) (11) are thermally connected to the trap body (8). As shown by arrow a in Fig. 4A, the vacuum chamber (11) on the right side is connected to the vacuum valve (2
Since the structure is such that almost 100% of the gas that has entered the cryotrap (3) through ) collides with (lO) or (Ill) of the 80K cryopanel, most of the moisture in the gas is exhausted.

Here, the 5th A is used as the conductance control valve (4).
Although the butterfly type conductance valve shown in the figure was used, any other type of conductance valve may be used as long as it can control conductance.

Components common to those in FIGS. 2 and 3 are given the same reference numerals.

In this embodiment, the process gas (argon) introduced into the vacuum chamber (1) is passed through the vacuum valve (2) and the cryotrap (3). It is evacuated by a cryogenic pump (5) through a conductance control valve (4). The pressure required for the sputtering process is regulated by a conductance control valve (4).

That is, since the cryotrap (3) is located before the conductance control valve (4) that throttles the flow rate of exhaust gas, the resistance to gas flow is small and the water pumping speed can be increased. When the conductance is narrowed, as in the conventional device with a conductance valve installed in front of a cryopump with a cryotrap, the resistance to gas flow increases, reducing not only the pumping speed for process gas but also the pumping speed for water. There is no such thing as doing it.

In this way, the cryotrap (3) is not affected by the adjustment of the conductance control valve (4), so moisture that is unfavorable to the process is evacuated by the cryotrap (3) at the same pumping speed as in the high vacuum pumping state. , a high-quality process atmosphere can be obtained.

The embodiments of the present invention have been described above, but of course the present invention is not limited thereto, and various modifications can be made based on the technical idea of the present invention.

For example, in the embodiment, a Talio pump is used to exhaust the process gas, but the same effect can be obtained by using a turbo molecular pump instead. Turbomolecular pumps have the disadvantage of having a lower pumping speed for water than cryopumps, but by combining them with cryotraps as in the present invention, pumping characteristics equivalent to those of cryopumps can be obtained.

[Effects of the Invention] Since the present invention has the above-described configuration, it is possible to adjust the process pressure to a desired level without reducing the pumping speed for water, and to obtain a high-quality process atmosphere.

[Brief explanation of drawings]

FIG. 1 is a schematic side view showing a vacuum evacuation device according to an embodiment of the present invention, FIGS. 2 and 3 are schematic side views showing conventional vacuum evacuation devices, and FIGS. 4A and 4B are cryo-exhaust devices. A partially sectional side view and a partially broken front view showing an example of a trap, and FIGS. 5A and 5B are perspective views showing an example of a conductance control valve, respectively. In the figure, (1)... Vacuum tank (3)...
・・・・・・Cry Sai Trap (4)・・・・・・
・・・・・・Conductance valve (5)・・・・・・−
・1・・Cryopump agent Osamu Yasushi Saka No. 1 Figure 3−=−゛゜Cryotrap 4・・・Conduct 9th control valve 5・・・
・・・゛Cryopump Figure 2 1 Figure 4B

Claims (1)

[Claims] 1. A vacuum evacuation device, characterized in that, in an evacuation path connecting a vacuum chamber and a vacuum pump, a cryotrap is provided on the side of the vacuum chamber, and a conductance control valve is provided between the cryotrap and the vacuum pump.