JPH01310541A - Etching device - Google Patents

Abstract

PURPOSE:To cut down the labor and time for maintenance by a method wherein a purifying train to purity the exhaust gas during evacuation is provided between high and low vacuum pumps in an exhaust route. CONSTITUTION:An etching mechanism is built-in a vacuum vessel 1 while an exhaust route 2 communicating the vacuum vessel 1 with atmospheric air is provided. Then, a high vacuum pump 3 is provided on this exhaust route 2 evacuate the vacuum vessel 1 to the high vacuum. Besides, a low vacuum pump 4 is provided on the part nearer to the atmospheric air side than the high vacuum pump 3 on the exhaust route 2 to evacuate the vacuum vessel 1 to the low vacuum. Furthermore, a purifying train is provided between both vacuum pumps 3 and 4 on the exhaust route 2 to purify the exhaust gas during evacuation. Through these procedures, the maintenance period of the low vacuum pump 4 can be extended to cut down the labor and time for the maintenance.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in an etching apparatus for processing, for example, microfabrication of a film formed on a semiconductor silicon wafer.

(Prior art j Figure 2 is shown in, for example, Japanese Unexamined Patent Publication No. 59-112623! v In all, 1] is a vacuum vessel with a built-in etching mechanism, and c2) is a vacuum vessel α] that communicates with the atmosphere. an exhaust system path consisting of an exhaust pipe (2a) or 2d) provided as a
) is a high vacuum pump such as a mechanical booster bong, which is provided between the exhaust system path (2b) and (2c) and evacuates the inside of the vacuum container (1) to a high vacuum; (4) is the exhaust system path (2C); (2d) The high vacuum pump (3) is a low vacuum pump, such as a rotary pump, which is installed on the atmosphere side and evacuates the inside of the vacuum container to a low vacuum, and (5) is the exhaust system path (
2! L).

(2b) A pressure control device is installed between the vacuum container U) and the high vacuum pump (3) to adjust the pressure inside the vacuum container during etching.

Next, the effect will be explained. For example, in etching processing such as microfabrication of a film formed on a semiconductor silicon wafer, the inside of the vacuum container (1) is first evacuated to a rough vacuum by operating the low vacuum pump (4), and then the inside of the vacuum container (1) is evacuated to a rough vacuum by the operation of the low vacuum pump (4). pump(
By the operation of step 3), the chamber is evacuated to a high vacuum, a predetermined degree of vacuum is obtained by the pressure control device (5), and the etching process is started. At the same time, a reaction product (not shown) is generated in the vacuum container (1), and this reaction product passes through the exhaust system path (2) together with the exhaust gas (not shown) that is being exhausted. and is exhausted.

[Problem to be Solved by the Invention J] Since the conventional etching apparatus is configured as described above, when the reaction products contained in the exhaust gas pass through the exhaust system, a part of them is removed from each equipment and piping. Adheres to the inside of.

Particularly in low-vacuum pumps that use oil rotary pumps such as rotary pumps, reaction products may get mixed into the oil.
Adhesion and deposition inside the pump is significant under conditions where the temperature is such that reaction products tend to adhere (at low temperatures below room temperature). In this state, the interior of the low-vacuum pump, which has a relatively low degree of vacuum, is often exposed to the atmosphere, and the reaction products absorb moisture from the atmosphere and become strong acids, causing metal corrosion and shortening the life of the pump.

For this reason, there were problems such as the cycle of maintenance such as cleaning inside the pump and oil change had to be extremely shortened, which required time and effort.This invention was made to solve the problems mentioned above. To provide an etching device capable of extending the maintenance cycle of a low vacuum pump and reducing the effort and time required for maintenance.

[Means for Solving the Problems] An etching apparatus according to the present invention includes a vacuum container in which an etching mechanism is built, an exhaust system path that communicates the vacuum container with the atmosphere, and an exhaust system path that connects the vacuum container with the atmosphere. A high vacuum pump is provided to evacuate the inside of the vacuum vessel to a high vacuum, a low vacuum pump is provided on the atmosphere side to evacuate the inside of the vacuum vessel to a low vacuum, and both vacuum pumps are provided in the exhaust line path. A purification device is provided between the vacuum exhaust gas and a purification device for purifying the exhaust gas in the vacuum exhaust gas.

[Operation j] In the etching apparatus of the present invention, the purification device captures reaction products contained in the exhaust gas before the low vacuum pump.

[Embodiments of the invention] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a schematic system of an etching apparatus according to the present invention. In the figure, elements (1) to 5) are the same as the conventional structure shown in FIG. 2, and therefore their explanation will be omitted. (6) has a purifying liquid such as vacuum oil inside (
A purification container storing 7) with a space (6a) left over, (8)
One side communicates with the exhaust system line (2C) at the high vacuum pump (3) side branch point (8b), and the other side passes through the purification container (6) and has a bubbling nozzle (8a) shape at the tip. Purification liquid (7)
The inlet communication pipe (9), which is immersed inside and communicates with the purification liquid, has one side connected to the exhaust system line (2) and the low vacuum pump (4) (j111 branch point (9b)), and the other side to the purification container (6 ), and the inlet port (9a) at the tip communicates with the space (6a), the outlet side communication pipe (10) is between the branch point (8b) and (9b) of the exhaust system path (2c) and the inlet side communication pipe. These are vacuum valves installed in each pipe.These purification containers (6), purification liquid (7), inlet communication pipe (8), and source communication pipe (9) constitute a purification device (11). There is.

The operation of one embodiment configured as described above will be explained.

In the etching process, first, the inside of the vacuum container (1) is roughly evacuated by operating the low vacuum pump (5), but in this case, no reaction products are generated, so the inlet side communication pipe (
8) By closing the Q vacuum valve (10) and opening the vacuum valve (10) in the exhaust system line (2c), the vacuum exhaust gas passes through the exhaust system line (2c) and passes through the low vacuum pump (4) to the system. released outside. Next, the high vacuum pump (3) is operated to obtain a predetermined degree of vacuum and the etching process is performed. In this case, each vacuum valve (10) opens the inlet communication pipe (8) side and exhausts the exhaust system path (2c).
(Equipment to purify vacuum exhaust gas by closing Qll (11)
Convert it into a thread path. In this state, the reaction products generated in the vacuum vessel (1) by the etching process are passed through the inlet side communication pipe (8) together with the vacuum exhaust gas through the bubbling nozzle /L/ (
8a) Fine bubbles are discharged into the cleaning liquid (7). The reaction products in the vacuum wandering gas discharged into the liquid are dissolved or precipitated in the purification liquid (7) and removed, and the purified vacuum exhaust gas passes through the space (6a) and exits from the suction port (9a). It passes through the communication pipe (9) and is discharged out of the system through the low vacuum pump (4). In addition, by providing a cooling mechanism (not shown) such as a cooling pipe in the purified liquid in the above-mentioned embodiment, it is effective to cool the purified liquid so that reaction products can be captured in the liquid.

In addition, in the above examples, the reaction products were captured using a purification liquid.
The same effect as in the embodiment can also be obtained by providing a reaction product removal device having cryogenic conditions, such as a liquid nitrogen trap, at the same position in the exhaust system.

f Effects of the Invention J As described above, according to the present invention, there is provided a vacuum container in which an etching mechanism is built, an exhaust system path provided to communicate the vacuum container with the atmosphere, and an exhaust system path provided in the exhaust system path. Between the high vacuum pump that evacuates the inside of the vacuum container to a high vacuum, the low vacuum pump that is installed on the atmosphere side of the vacuum bonder in the exhaust system path and evacuates the inside of the vacuum container to a low vacuum, and both vacuum pumps in the exhaust 9C system path. Since the etching device is provided with a purifying device for purifying the exhaust gas in the vacuum exhaust gas, the maintenance cycle of the low vacuum pump can be extended, and an etching device that requires less effort and time for maintenance can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a schematic system of an etching apparatus according to an embodiment of the present invention, and FIG. 2 is a diagram showing a schematic system of a conventional etching apparatus. In the figure, α) is the vacuum vessel, (2) is the exhaust system path, and (3
) is a high vacuum pump 1, (4) is a low vacuum pump, and (12) is a purification device. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. Agent Masuo Oiwa Figure 1 Figure 2

Claims (1)

[Claims] A vacuum container with a built-in etching mechanism, an exhaust system path provided to communicate the vacuum container with the atmosphere, and a high vacuum pump provided in the exhaust system path to evacuate the inside of the vacuum container to a high vacuum; A low vacuum pump is provided on the atmosphere side of the vacuum pump in the exhaust system and evacuates the inside of the vacuum container to a low vacuum, and a low vacuum pump is provided between the two vacuum pumps in the exhaust system to purify the exhaust gas being evacuated. Etching equipment equipped with a purification device.