JP3309228B2 - Cryopump device with turbo molecular pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cryopump device used for a vacuum device such as a sputtering device and an ion plating device.

[0002]

2. Description of the Related Art FIG. 1 shows a conventional exhaust system in which a condensable gas such as argon or nitrogen and a non-condensable gas such as hydrogen or helium are used in a vacuum apparatus. Further, there is known an exhaust device in which a cryopump c is connected to a vacuum device a via a vacuum valve b, and a turbo-molecular pump e is connected in parallel with the cryopump c via a vacuum valve d. In this exhaust device, the exhaust system of the cryopump c and the exhaust system of the turbo-molecular pump e are completely independent of each other. The condensable gas is exhausted by the cryopump c, and the non-condensable gas is exhausted by the turbo-molecular pump e. The pumps exhaust each other, compensating for their lack of performance. That is, the turbo molecular pump e has a low pumping speed for condensable gas (particularly water), whereas the cryopump c has a high pumping speed for condensable gas. In addition, the cryopump c cannot exhaust a large amount of non-condensable gas, but the turbo molecular pump e can continuously exhaust the gas. Can complement each other. An adsorbent that adsorbs non-condensable gas is installed inside the cryopump, and the non-condensable gas is exhausted with this. However, when a turbo molecular pump is provided, the adsorbent is a cryopump. c, the cryopump cannot exhaust any non-condensable gas. The condensable gas introduced into the vacuum device a is exhausted by the cryopump c, and the non-condensable gas is exhausted by the turbo molecular pump e. However, when the vacuum device a is a sputtering device or an ion plating device, Since the pumping speed of the cryopump c with respect to the argon gas is too high, the valve b is narrowed and the pumping speed is reduced. However, when argon gas is not used in the vacuum device a,
The valve b is fully opened to achieve a high vacuum quickly.

Further, as shown in FIG. 2, an exhaust device in which a cryopump c and a turbo molecular pump e are vertically connected in series to a vacuum device a is also used. Details of this are as shown in FIG. 3, in which the condensable gas is captured by the cryopump c at the preceding stage, and the non-condensable gas passing through the cryopump c is exhausted by the turbo molecular pump e. In this case, upper and lower cylindrical shield panels 1 are provided in the pump case f of the cryopump c, and horizontal bar-shaped 80K baffles h, h are provided above and below the shield panels 1 and are horizontally disposed therebetween. Is provided with a multiple umbrella-shaped 15K cryopanel g, a gas inlet i above the pump case f, and an opening j connecting the high vacuum port of the turbo molecular pump e below the pump case f. The cryopanel g and the baffle h To the refrigerator k attached to the pump case f and
And cool to 80K.

[0004]

Used INVENTION Problems to be Solved] vacuum device a in an argon gas such as a sputtering apparatus is large, usually argon pressure of 10 ^{- 3-10 -} at about ² Torr, the pressure is very for the turbo molecular pump e Therefore, in the case of FIG. 1, a wideband turbo-molecular pump capable of using a high pressure is used. This broadband turbomolecular pump has the disadvantage that the internal structure is complicated and expensive.

The examples shown in FIGS. 2 and 3 are of a type devised to overcome the drawbacks of FIG. 1, in which a cryopump c is arranged in series directly above a turbo molecular pump e. The condensable argon is exhausted by the cryopump c and hardly flows into the turbo molecular pump e. Therefore, the pressure at the high vacuum port of the turbo-molecular pump e can be reduced, and an expensive broad-band type is not required, and a low-cost standard turbo-molecular pump can be used. However, in this example, due to the structure, the 15 K
Due to the presence of the cryopanel g, there is a danger that the argon or moisture (ice) condensed on the cryopanel g will fall directly into the turbo molecular pump e. The rotor of the turbo molecular pump e normally rotates at high speed during operation,
If a small foreign object falls on it, it often leads to a catastrophic failure such as destruction of the rotor blades.Therefore, this type of exhaust device is used for vacuum equipment that exhausts a large amount of condensable gas such as sputtering or ion plating. Not applicable. In the example shown in FIG. 1, there is no danger of the turbo molecular pump e being destroyed by the fall of argon, but there is a drawback that the heat load is increased.

SUMMARY OF THE INVENTION An object of the present invention is to provide a cryopump apparatus which can exhaust a large amount of condensable gas without failure due to falling of condensate using a standard type turbo molecular pump.

[0007]

According to the present invention, a cup-shaped shield panel connected to a refrigerator having an opening to the inlet is provided inside a pump case of a cryopump having a gas inlet above. A cryopanel connected to the refrigerator inside the shield panel, and a high vacuum port of the turbo-molecular pump connected to an opening formed in the pump case. The port was connected to an opening provided on the side of the pump case, and an intake port facing the opening was provided on the side of the shield panel.

[0008]

The refrigerator of the cryopump is operated to cool the shield panel to about 80K and the cryopanel to about 15K. The vacuum valve is opened and the gas inlet is adjusted to an appropriate vacuum pressure. Connecting. And
When the turbo molecular pump is operated, the gas in the vacuum device flows to the turbo molecular pump via the cryopump, the condensable gas is condensed and discharged to the shield panel and the cryopanel, and the non-condensable gas is turbocharged. It is evacuated by a molecular pump. Although such an operation is the same as the example shown in FIG. 2, in the apparatus of the present invention, an inlet is provided on the side of the shield panel so as to face the opening for connecting the turbo molecular pump on the side of the pump case of the cryopump. Because it was
Even if condensate condensed on the shield panel or cryopanel falls, it does not enter the turbo molecular pump, and a vacuum device that uses a large amount of condensable gas using an inexpensive standard turbo molecular pump is used for high vacuum. Can be exhausted.

[0009]

Embodiment An embodiment of the present invention will be described with reference to FIG.
Reference numeral 1 denotes a cryopump provided with a gas inlet 2 above, and the gas inlet 2 is illustrated in a vacuum apparatus such as a sputtering apparatus or an ion plating apparatus which uses a large amount of condensable gas such as argon gas. Not connected via a vacuum valve. The cryopump 1 includes a cup-shaped shield panel 5 having an opening 4 to the inlet 2 inside a cylindrical pump case 3, and a cryopanel 6 is provided inside the shield panel 5. Reference numeral 7 denotes a baffle provided in the opening 4 of the shield panel 5. The shield panel 5 is a first-stage cold head 9a of the refrigerator 8
And the cryopanel 6 is attached to the second-stage cold head 9b of the refrigerator 8.

[0010] 10 of about 10 ^- at ³ Torr or less standard turbo molecular pump for evacuating operating at high vacuum, high vacuum port 11 of the pump casing 3 of the cryopump 1 of the pump 10
Was connected via a vacuum valve 16 to the opening 12 formed on the side of the. The air supply port 1 facing the opening 12 in the shield panel 5
4 is provided so that a part of the gas flowing from the gas inlet 2 is exhausted by the turbo-molecular pump 10 through the air supply port 14. The gap between the pump case 3 and the shield panel 5 is manufactured at a narrow interval through which a condensable gas (eg, argon) hardly passes. In the illustrated example, a flange 15 is formed around the opening 12 and a high vacuum port 11 of the turbo-molecular pump 10 is formed therethrough via a vacuum valve 16.
And a flange 17 is provided around the air supply port 14 to extend into the inside of the opening 12 so that the gas flowing from the gas inlet 2 is guided to the turbo molecular pump 10 without fail. The refrigerator 8 can be attached to the side of the pump case 3 as shown in FIG. Turbo molecular pump 10
May be omitted in some cases.

[0011] The apparatus of this embodiment, 10 in advance roughing pump vacuum device ^- connected After evacuated to about ³ Torr,
Prior to the connection, the shield panel 5 is cooled to about 80K by the refrigerator 8 and the cryopanel 6 is cooled to about 15K.
After that, the vacuum valve is opened and connected to a vacuum device through the gas inlet 2, and the turbo molecular pump 10
Activate Thereby, the gas in the vacuum device flows to the turbo molecular pump 10 via the cryopump 1, the condensable gas is condensed and discharged to the shield panel 5 and the cryopanel 6, and the non-condensable gas is 10
Exhausted by Such an exhaust operation is the same as the example shown in FIG. 2, but the apparatus of this embodiment faces the opening 12 for connecting the turbo molecular pump 10 on the side of the pump case 3 and the intake port 14 on the side of the shield panel 5. Therefore, even if a large amount of condensable gas is used in a vacuum device and a large amount of condensate condenses on the baffle 7 and the cryopanel 6 of the shield panel 5 and the condensable gas falls, the condensate is turbocharged. It is safe because it does not enter the molecular pump 10.
Further, since only the non-condensable gas flows into the turbo-molecular pump 10, a vacuum apparatus using a large amount of condensable gas can be evacuated to a high vacuum by using an inexpensive standard type instead of a broadband type.

[0012]

As described above, according to the present invention, the turbo molecular pump is connected to the opening formed on the side of the pump case of the cryopump, and the suction port facing the opening is provided on the side of the shield panel. Therefore, a vacuum device such as a sputtering device that generates a large amount of condensate in the cryopump can be evacuated to a high vacuum using a standard inexpensive turbo-molecular pump so as not to cause a failure due to the condensate, The structure is relatively simple and has an effect that it can be manufactured at low cost.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a conventional example.

FIG. 2 is an explanatory view of another conventional example.

FIG. 3 is a sectional view showing a specific structure of FIG. 2;

FIG. 4 is a cutaway side view of an embodiment of the present invention.

FIG. 5 is a cutaway side view of another embodiment of the present invention.

[Explanation of symbols]

1 Cryopump 2 Gas inlet 3
Pump case 5 Shield panel 6 Cryopanel 8
Refrigerator 10 Turbo molecular pump 11 High vacuum port 1
2 opening 14 air supply port 15, 17 flange

Claims (3)

(57) [Claims] 1. A cup-shaped shield panel connected to a refrigerator having an opening to the inlet is provided inside a pump case of a cryopump having a gas inlet at an upper part thereof,
A cryopanel connected to the refrigerator is provided inside the shield panel, and a high vacuum port of a turbo molecular pump is connected to an opening formed in the pump case.
A high vacuum port of the turbo-molecular pump is connected to an opening provided on a side of the pump case, and an intake port facing the opening is provided on a side of the shield panel. . 2. The cryopump device with a turbo-molecular pump according to claim 1, wherein the refrigerator is mounted below or beside the pump case. 3. A high vacuum port of the turbo-molecular pump is connected via a flange provided around an opening of the pump case, and a flange is provided around an air supply port of the shield panel to enter the inside of the opening. The cryopump with a turbo-molecular pump according to claim 1, wherein: