JPS59133365A - Vacuum device - Google Patents

Abstract

PURPOSE:To prevent soaring up of foreign matter in a vapor deposition chamber during evacuation and introduction of atmospheric air by providing means for controlling the flow rate in the viscous fluid region of gas in both of an evacuation section and an atmospheric air introducing section respectively in a vacuum deposition device. CONSTITUTION:An evacuating piping 3 and an atmospheric air introducing pipe 9 are provided in a vacuum deposition chamber 2. A rotary pump 4 for pre- vacuuming is installed in the former and a pre-vacuuming valve 5 is interposed between the pump and the piping 3. A bypass 6 for slow evacuation is further connected in parallel therewith and a flow rate control valve 7 and a slow evacuating valve 8 are installed thereto. A diffusion pump 14 is separately provided as a pump for final evacuating. A vent valve 10 is interposed in the pipe 9 and a bypass 11 for slow ventilation provided with a slow vent valve 12 and a flow rate control valve 13 is provided as a flow rate control means. The soaring up of foreign matter owing to a disturbance in gaseous flow is prevented when the above-mentioned device is operated by the sequence shown in the figure in the stage of evacuating and introducing atmospheric air.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vacuum device that can suppress foreign matter from being rolled up in a deposition chamber, which is a processing chamber.

As is well known, vacuum equipment such as vacuum evaporation equipment is used.

For example, it is used when forming a metal vapor deposition film on the surface of a semiconductor wafer.

When performing this vapor deposition, it is necessary to first make the vapor deposition chamber of the apparatus a high vacuum (and after the vapor deposition is completed, it is necessary to return the pressure inside the vapor deposition chamber to atmospheric pressure.

Conventionally, the vacuum evaporation equipment has two evaporation chambers as shown in Figure 3.
2, a roughing rotary pump 24 is connected to one side of the vapor deposition chamber 22, and a roughing valve 23 is interposed between them, thereby performing roughing during vacuum evacuation. Next, a diffusion pump 34 and an auxiliary rotary pump 36 are connected to the lower part of the vapor deposition chamber 22 to perform main pulling. Furthermore, vent pulp 3 is placed in the other side of the vapor deposition chamber 22.
The structure was such that the atmosphere was introduced into the vapor deposition chamber 22 by connecting 0 to the vapor deposition chamber 22.

However, in a structure like this.

The gas flow is disrupted during evacuation and air introduction.

Foreign matter in the vapor deposition chamber 22 was rolled up and attached to the wafer surface, resulting in a decrease in yield due to wafer vapor deposition.

(The above-mentioned curling up phenomenon becomes a problem in the deposition chamber 2.
The state of the gas in 2 is in the viscous flow region, for example atmospheric pressure ~ 5
Problems arise in the range up to X 10""' Torr.

The present invention aims to eliminate these drawbacks of conventional vacuum equipment, and its purpose is to provide a vacuum equipment that can process semiconductor wafers in a clean processing chamber by suppressing foreign matter from rolling up inside the processing chamber. It is on offer.

Embodiments of the present invention will be described below with reference to the drawings with ti.

FIG. 1 is a system diagram of a vacuum evaporation apparatus according to an embodiment of the present invention. In the figure, this vacuum evaporation apparatus 1 has a evaporation chamber 2 in the middle, and on one side of this evaporation chamber 2, an evacuation pipe 3, which constitutes a part of the evacuation part, is attached. A rotary pump 4 as a roughing pump is provided at the tip, and at the same time, a roughing valve 5 is interposed between the rotary pump 4 and the pipe 3 connecting the vapor deposition chamber 2.

Further, a slow exhaust bypass 6 is connected so as to straddle the roughing valve 5, and a flow control valve 7 and a slow exhaust valve 8 are connected to the bypass 6 as a flow rate control means.
are installed sequentially from the deposition chamber 2 side.

In addition, on the opposite side of the vapor deposition chamber 20, a part of the atmosphere introduction part is constructed.
A vent valve 10 is interposed in the middle of the pipe 9.

A slow vent bypass 11 is connected to the piping 9 across this vent valve 10, and a slow vent valve 12 and a flow control valve 13 as flow rate control means are arranged sequentially from the farthest position from the vapor deposition chamber 2. .

Further, a diffusion pump 14 as a main pump is provided in the lower part of the deposition chamber 2, and is connected via a pipe 15 to a rotary pump 16 as an auxiliary pump.

Next, the evacuation operation and the atmosphere introduction operation in the vacuum evaporation apparatus 1 configured as described above will be explained using FIG. 1 and FIG. 2 1al and 1bl.

First, as shown in lal, the deposition chamber 2 must be brought from atmospheric pressure to an appropriate degree of vacuum (in order to do so, a vacuum evacuation operation must be performed).

To do this, first roughly reduce the flow rate with the flow rate control knob 7, and then use the slow exhaust valve 8 to roughly reduce the flow rate in the viscous flow region of the gas to a level that does not cause turbulence. Pull with rotary pump 4 for pulling.

Next, the rough evacuation valve 5 is opened, and the rotary pump 4 is used to perform a rough evacuation that is more rough than the slow evacuation valve 8.

Up to this point, vacuum evacuation has been carried out targeting the viscous flow region of gas, but then a main evacuation operation is started which targets a region other than the viscous flow region, for example, the molecular flow region.

Needless to say, this main pull is the diffusion pump 14.

This is carried out using a rotary pump 16 connected to this,
Obtain high vacuum conditions.

In this state, predetermined vapor deposition is performed within the vapor deposition chamber 2.

That is, after the metal vapor deposition film is formed on the surface of the wafer, the above-described air introduction operation is performed.

This air introduction operation is to return the pressure (high vacuum) inside the deposition chamber 2 to atmospheric pressure, and as shown in lbl, first the flow rate in the viscous flow region of the air taken in by the slow vent valve 12 is reduced. The gas is squeezed to a level that does not cause disturbance, and is further regulated by a flow rate control valve 7 before being introduced into the deposition chamber 2.

After that, the pressure in the deposition chamber 2 is returned from the high vacuum state to the atmospheric pressure state by opening the vent valve 10 and introducing atmospheric air into the deposition chamber 2 at a flow rate lower than that of the introduction section by the slow vent valve 12. be able to.

In the above embodiment, a Kerslow vent valve 12 and a flow rate control valve 13 are installed on the atmosphere introduction side.
The most preferable arrangement order is as shown in Figure 1.
If you switch these positions, immediately after opening the slow vent valve 12, open the flow control valve 13.
The gas present between the valve and the slow vent valve 12 flows in.

This should be avoided as it will cause a sudden increase in pressure ('1
The same thing occurs with the flow rate control valve 7 and the slow ventilation valve 8 on the evacuation section side, so the arrangement shown in FIG. 1 is desirable.

However, in this case, the pressure difference before and after the slow exhaust valve 8 is smaller than in the case of the slow bend valve 12, so even if the arrangement is reversed, the effect will be small.

As is clear from the above description, according to the vacuum device according to the present invention, means for controlling the flow rate in the viscous flow region of gas are provided in both the vacuum evacuation section and the atmosphere introduction section of the vacuum device, respectively. At the beginning of the vacuum evacuation process and the initial stage of the air pressure control process, the gas flow section is squeezed to prevent turbulence in the gas flow as much as possible, so there is no foreign matter being stirred up in the processing chamber as in the case of conventional methods, and the wafer This allows the treatment to be performed on the object in a clean state.

[Brief explanation of the drawing]

FIG. 1 is an exhaust system diagram of a vacuum evaporation apparatus according to an embodiment of the present invention, FIG. It is an exhaust system diagram. DESCRIPTION OF SYMBOLS 1... Vacuum deposition apparatus, 2... Vapor deposition chamber, 3... Vacuum exhaust piping, 4... Rotary pump, 5... Roughing valve, 6... Bypass for slow exhaust, 7...・・Flow rate control valve %8・・°Slow exhaust valve, 9
...Air introduction piping, 1o...Vent valve, 11
... Slow vent-bypass % 12... Slow vent-valve, 13... Current control valve, 1
4... Diffusion pump, 15... Piping, 16... Rotary pump, 21... Vacuum deposition device, 22... Vapor deposition chamber, 23... Roughing valve, 24... For roughing Rotary pump, 30...Vent valve, 34...Diffusion pump, 36...Auxiliary rotary pump. Figure 1 Figure 2 Figure 1! Y-ki
(ty-) Figure 3 Δ

Claims (1)

[Claims] 1. A vacuum evacuation section for bringing the processing chamber into a vacuum state. and an atmosphere introduction part for bringing the processing chamber to atmospheric pressure. A vacuum apparatus comprising: a flow rate adjusting means for preventing gas turbulence in the processing chamber provided in either the vacuum evacuation section or the atmosphere introduction section.