JPH108250A - Sputtering equipment - Google Patents

Abstract

(57) Abstract: Provided is a sputtering apparatus capable of improving the degree of vacuum by completely isolating a vacuum pumping section between a reaction chamber and a load lock chamber. SOLUTION: The present invention separates a vacuum luffing means capable of roughing a reaction chamber and a load lock chamber from an atmospheric state to a low vacuum state, and a means for pumping the reaction chamber to a high vacuum, and separates them. A first pumping means for pumping the load lock chamber into a high vacuum state, and a vacuum leak caused by the reaction chamber and the load lock chamber forming the same space each time a wafer is transferred can be prevented. A second pumping means for pumping to a high vacuum state, and a number of valves for opening and closing a vacuum line communicated with the reaction chamber and the load lock chamber by operation of the means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sputtering apparatus, and more particularly, to a sputtering apparatus capable of improving the degree of vacuum of a sputtering equipment used in a semiconductor manufacturing process.

[0002]

2. Description of the Related Art In general, sputtering for manufacturing a semiconductor is a device for forming an electrode or wiring by laminating a metal film such as aluminum (Al) or titanium (Ti) on a semiconductor wafer. That is, the sputtering is performed, for example, using argon (Ar).
When a high voltage is applied to a reaction chamber in which an inert gas such as a gas is present, metal atoms such as Al fly out of a negatively charged metal target in a strong electric field and are stacked as a thin film on a wafer. . At this time, the pressure inside the reaction chamber must maintain a high vacuum state of about 5 × 10 ⁻⁷ Torr.

A conventional apparatus for maintaining such a high vacuum state is disclosed, for example, in US Pat.
FIG. 2 schematically shows a 180 model sputtering apparatus. Referring to FIG. 2, the conventional apparatus maintains a high / low vacuum state in the reaction chamber 1 and the load lock chamber 2 by operating the same cryopump 3 and mechanical pump 4. At this time, the state of the vacuum is adjusted through a plurality of valves installed in a plurality of connected vacuum lines. That is, the reaction chamber 1 is operated by the mechanical pump 4 so that a differential pump-out valve (differential pump-out valve) is provided.
Roughing (roughing) is performed so as to maintain a low vacuum state through an mp Out Valve (Vout Valve) V7. maintain.

On the other hand, in order to create a preliminary environment for a wafer process in which the load lock chamber 2 is loaded / unloaded into the reaction chamber 1, first, the mechanical pump 4 is operated to reduce the atmospheric pressure to 100 mm Torr or less from the atmospheric state. When roughing to a low vacuum state, a load lock isolation valve (Load Lock Isolation Valve) V2 and a load lock rough valve (Lord Rock Rough Va) are used.
lve) V3 is released. Thereafter, to maintain the load lock chamber 2 in a high vacuum state, the load lock rough valve V3 is closed, but the load lock isolation valve V2 and the load lock high vacuum valve V4 are opened to close the load lock rough valve V3. The pumping force of the climbing pump 3 comes to work.

[0005]

However, in order to load / unload the wafer into / from the reaction chamber 1 when the process is performed by the load lock method, the wafer must pass through the load lock chamber 2. The vacuum state of the reaction chamber 1 continues to deteriorate as the process proceeds. The cause of the deterioration of the vacuum state of the reaction chamber 1 and the problems associated therewith will be described as follows. First, the reaction chamber 1 and the load lock chamber 2 are the same cryopump 3
As a result, a considerable amount of air molecules existing in the load lock chamber 2 are released by opening the load lock high vacuum valve V4 as shown by the arrow in FIG. Backflow into This results in that good film quality cannot be deposited on the wafer because the degree of vacuum in the reaction chamber 1 is deteriorated.

Second, the reaction chamber 1 and the load lock chamber 2
Is roughened to a low vacuum state by the mechanical pump 4, the pumped air flows backward through the differential pump-out valve V7 and the load lock differential pump-out valve V8 as shown by the arrow in FIG. Luffing vacuum leaks little by little. This is because the transfer plate (not shown) in the reaction chamber is rotated each time a wafer is transferred, and the reaction chamber 1 and the load lock chamber 2 become one chamber. As in the first problem, it adversely affects the degree of vacuum in the reaction chamber 1 and causes poor deposition of the metal film. Accordingly, the present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to completely separate a vacuum pumping portion between a reaction chamber and a load lock chamber, thereby improving a vacuum degree. To provide a vacuum pump device.

[0007]

According to the present invention, there is provided a vacuum pump apparatus for sputtering, which is capable of roughing a reaction chamber and a load lock chamber from an atmospheric state to a low vacuum state. Roughing means,
Separated from the means for pumping the reaction chamber to a high vacuum,
A first pumping means for separately pumping the load lock chamber to a high vacuum state; and preventing leakage of vacuum due to the reaction chamber and the load lock chamber forming the same space each time a wafer is transferred. And second pumping means for pumping to a high vacuum state as much as possible.

[0008]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a configuration diagram schematically showing a sputtering apparatus according to an embodiment of the present invention, with particular emphasis on a vacuum evacuation system. FIG.
, A sputtering apparatus A generally includes a reaction chamber 10, a load lock chamber 20 for forming a preliminary environment for a wafer process loaded / unloaded into the reaction chamber 10,
A vacuum exhaust system 100 for exhausting the reaction chamber 10 and the load lock chamber 20 is provided.

The vacuum evacuation system 100 mainly comprises a cryopump 30, vacuum roughing means 40, first pumping means 50, second pumping means 60, and a plurality of vacuum lines connecting these. The cryopump 30 is formed integrally with the reaction chamber 10, and a valve V1 is provided between the two.

The vacuum roughing means 40 is constituted by a dry pump (hereinafter referred to as "dry pump"), and the dry pump 40 and the load lock chamber 20 are connected by a roughing line L1, which is a first vacuum line. Are linked. The luffing line L1 includes a load lock isolation valve V2 and a load lock rough valve V that open and close the luffing line L1 in order from the load lock chamber 20 side to the dry pump 40 side.
3 and a valve V6 are provided. Between the dry pump 40 of the roughing line L1 and the valve V6, the second
Is connected to one end of the vacuum line L2. The second vacuum line L2 is connected to the cryopump 30 at the other end via a valve V5.

The first pumping means 50 comprises a first turbo pump 52 and a first mechanical pump 54. A valve V9 is provided between the first turbo pump 52 and the first mechanical pump 54.
The first turbo pump 52 and the first mechanical pump 54 are connected between the load lock isolation valve V2 and the load lock rough valve V3 by a third vacuum line L3 branched from the roughing line L1. It is connected to the roughing line L1. This third
The vacuum line L3 has a load lock high vacuum valve V4 between the first turbo pump 52 and the branch point.
Is provided.

The second pumping means 60 comprises a second turbo pump 62 and a second mechanical pump 64. A valve V10 is provided between the second turbo pump 62 and the second mechanical pump 64. The second turbo pump 62 is connected to the reaction chamber 1 by a fourth vacuum line L4, which is a first differential line, via a differential pump out valve V7.
Connected to 0. On the other hand, the second pumping means 60 is connected to the load lock chamber 20 by a second differential line L5 branched from the first differential line L4 between the reaction chamber 10 and the differential pump-out valve V7. ing. A load lock differential pump-out valve V8 is provided between the branch point and the load lock chamber 20.

More specifically, the cryopump 30 operates the cryopump 30 to open the high vacuum valve V1 to maintain a high vacuum of about 5 × 10 -7 Torr.
On the other hand, the load lock chamber 20 is provided with a first pumping means 50 on a separate third vacuum line L3, and by operating the first pumping means 50, the load lock rough valve V3 is closed and the load lock chamber V3 is closed. A high vacuum state can be maintained by opening the lock isolation valve V2 and the load lock high vacuum valve V4.

Of course, when roughing the load lock chamber 20 to maintain a low vacuum state of about 10 -3 Torr from an atmospheric pressure state, the load lock high vacuum valve V
On the other hand, while closing the load pump 4, the load lock isolation valve V2 and the load lock rough valve V3 may be opened to operate the dry pump 40. in addition,
The first differential line L4 connected to the reaction chamber 10 and the second differential line L4 connected to the load lock chamber 20
The second pumping means 60 is separately installed on the differential line L5. The first differential line L4 and the second differential line L5 are provided with a differential pump-out valve V7 and a load lock differential pump-out valve V8, respectively.

As described above, the apparatus of the present invention comprises the reaction chamber 1
By completely isolating the pumping portion of the load lock chamber 20 from the zero, it is possible to prevent air molecules from flowing back into the reaction chamber 10 through the cryopump 30 as in the related art. Also, by separating the first differential line L4 and the second differential line L5 from the roughing line L1, when the second pumping means 60 is operated, the wafer is moved as described above. When the reaction chamber 10 and the load lock chamber 20 form one chamber, a slight leak of roughing vacuum can be prevented.

[0016]

As described above, according to the present invention, by completely isolating the pumping section between the reaction chamber and the load lock chamber, air molecules flow back into the reaction chamber through the cryopump as in the prior art. Can be prevented. Also, by separating the first differential line and the second differential line from the roughing line, the second pumping means is operated, and when the wafer is moved, the reaction chamber and the load lock chamber are the same. A slight luffing vacuum leak due to being a chamber can be prevented. Therefore, the degree of vacuum required for the sputtering process can be further improved, which greatly contributes to an improvement in manufacturing yield.

[Brief description of the drawings]

FIG. 1 is a configuration diagram schematically showing a sputtering apparatus according to an embodiment of the present invention.

FIG. 2 is a configuration diagram schematically showing a sputtering apparatus according to a conventional example.

[Explanation of symbols]

 Reference Signs List 10 reaction chamber 20 load lock chamber 30 cryopump 40 vacuum roughing means (dry pump) 50 first pumping means 52 first turbo pump 54 first mechanical pump 60 second pumping means 62 second turbo pump 64 second Mechanical pump

Claims (2)

[Claims] 1. A vacuum luffing means capable of roughing a reaction chamber and a load lock chamber from an atmospheric state to a low vacuum state; and a means for pumping the reaction chamber to a high vacuum.
First pumping means for separately pumping the load lock chamber to a high vacuum state; and preventing leakage of vacuum due to the reaction chamber and the load lock chamber forming the same space each time a wafer is transferred. And a second pumping means for pumping the reaction chamber and the load lock chamber to a high vacuum state. 2. The method according to claim 1, wherein the first and second pumping means include a turbo pump and a mechanical pump for pumping to a high vacuum so as to prevent a vacuum from flowing back into the reaction chamber. The sputtering apparatus according to claim 1.