JPH0214517A - Etching apparatus - Google Patents

Abstract

PURPOSE:To prevent a reaction product from adhering to an expansion joint by a method wherein an adhesion-preventing body used to prevent the reaction product between an active species and an etching material from adhering to the expansion joint is installed around the expansion joint. CONSTITUTION:A quartz outer tube 11 is fixed to an upper flange of a bellows 10; a quartz inner tube 12 is fixed to its lower flange in order to constitute an adhesion-preventing body together with the quartz outer tube 11. Then, when a high-frequency electrode 2 is moved downward, a double cylindrical shape which is overlapped by keeping a very small gap is formed. Accordingly, the bellows 10 is not exposed directly to a plasma owing to the adhesion- preventing body; it is possible to prevent an abnormal electric discharge from being caused at the bellows 10. In addition, a reaction product produced by a reaction between an active species and a wafer 7 is discharged through the neighborhood of the bellows 10 to the outside of a vacuum container 1 from a vacuum evacuation system 6; the bellows 10 is not exposed directly to the reaction product owing to the adhesion-preventing body; the reaction product does not adhere to the bellows 10.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an etching device including an expansion joint provided between a vacuum container and an electrode so as to provide a seal between the two.

[Prior Art] Fig. 3 is a cross-sectional view of a conventional etching apparatus disclosed in Japanese Patent Application Laid-open No. 100687/1987. In Fig. 1, (
1) is a vacuum container, (2> is a high-frequency electrode that is the first electrode that applies high-frequency waves, (3) is a ground electrode that is the second electrode that faces the high-frequency electrode (2), and (4) is a high-frequency power source. ,(
5) is a reaction gas supply system, and (6) is a vacuum exhaust system that creates a vacuum state and exhausts volatile reaction products from the reaction between the active species and the material to be etched to the outside of the vacuum container (1). System, (7) is the wafer as the material to be etched, (8
) is a quartz cylinder that prevents the wall surface of the vacuum container (1) from being exposed to plasma; (9) is a vertical drive device that is connected to the high-frequency electrode (2) and moves the high-frequency electrode (2) up and down;
) has one end attached to the high frequency electrode (2) and the other end attached to the vacuum container (1). ! It is a bellows as a hand.

Next, the e-operation of the above etching apparatus will be explained. The parameters for optimizing etching conditions are:
There are various factors such as applied power and reaction gas type, but one of them is the plasma density generated between electrodes (2) and (3) by changing the distance between parallel plate ZFm (2>, (3)). and the ion collision force may be optimized.

The distance between these electrodes <2> and (3) is the high frequency electrode (2).
A vertical drive device (9) connected to the high frequency electrode <2
) is moved up and down to set the appropriate distance a. When the high-frequency electrode (2) is driven up and down, the bellows (1O) ensures a tight seal between the vacuum container (1) and the vertical drive device (9), so the inside of the vacuum container (1) is under vacuum. Operated freely in any state.

Next, the reaction within the vacuum container (1) will be explained. When the wafer (7) is placed on the high frequency electrode (2) in vacuum, high frequency is applied with the high frequency power supply (4), and the reaction gas is supplied into the vacuum container (1) from the gas supply device (5), 1i (2 )
, (3) Plasma is formed between them, positive ions are accelerated by self-bypass, and active species collide with the wafer (a),
Etching is performed. During this reaction, the vacuum container (1)
In order to prevent abnormal discharge on the metal surface of the quartz cylinder (
8) is provided in the vacuum container (1).

[The invention attempts to solve i! ] In the conventional etching apparatus, the reaction products generated by reacting with the active species adhere to the parts in the container (1) after the reaction and gradually accumulate, and then they peel off and the wafer being etched (
In order to prevent this, a quartz cylinder (8
) established! has been done.

However, since there is no measure to prevent reaction products from adhering to the bellows (10), the reaction products tend to adhere and accumulate, resulting in poor etching due to dust generation from the bellows (10) and cleaning t11. There were problems such as an increase in frequency.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an etching device that prevents reaction products from adhering to an expansion joint.

[Means for Solving the Problems] The etching device according to the present invention is provided with an adhesion prevention body around the expansion joint to prevent the reaction product of the active species and the etching material from adhering to the expansion joint. be.

[Operation] In the present invention, the reaction product moving toward the expansion joint is blocked by the adhesion prevention body, and the reaction product does not adhere to the expansion joint.

[Examples] Examples of the present invention will be described below. FIG. 1 is a cross-sectional view showing one embodiment of the present invention, and the same or corresponding parts as in FIG. 3 are given the same reference numerals, and the explanation thereof will be omitted.

1], (11) is a quartz outer cylinder fixed to the upper flange of the bellows (10) and serving as an anti-adhesion body for preventing reaction products from adhering to the bellows (10);
2) is a quartz inner cylinder which is fixed to the lower flange and constitutes an adhesion prevention body together with the quartz outer cylinder (11), and (13) is a heater provided in the bellows (10). The quartz outer cylinder (11) and the quartz inner cylinder (12) are connected to a vertical drive device (9).
) When the high-frequency electrode (2) is moved downward by the drive of the high-frequency electrode (2), it takes on a double cylindrical shape that overlaps with a small gap as shown in FIG.

In the etching device configured as described above, the bellows (10) has a quartz outer cylinder (11) and a quartz inner cylinder 12).
Therefore, the bellows (10) is not directly exposed to plasma, and therefore abnormal discharge is prevented from occurring in the bellows (10). In addition, reaction products generated by the reaction between the active species and the wafer (7) are discharged from the vacuum exhaust system (6) to the outside of the vacuum container (1) through the vicinity of the bellows (10). 10) is not directly exposed to the reaction products due to the quartz outer cylinder (11) and the quartz inner fi (12), and there is no possibility that the reaction products will adhere to the bellows (10). (13), the bellows (10), the quartz outer cylinder (11), and the quartz inner cylinder (12) are heated, and by volatilization of the reaction products, the bellows (10)
This prevents reaction products from adhering to the quartz outer cylinder (11) and the quartz inner cylinder (12).

In addition, in the above embodiment, a quartz outer cylinder (11
), the quartz inner cylinder (12) has been described, but similar effects can be achieved with other materials such as fluoride resins and ceramics.

[Effects of the Invention] As explained above, the etching device of the present invention can prevent reaction products from adhering to expansion joints, prevent etching defects caused by dust generated by reaction products, and reduce the cleaning interval. This has the effect of significantly extending etching performance and improving maintainability.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing one embodiment of the present invention, FIG. 2 is a cross-sectional view showing another mode of use of FIG. 1, and FIG. 3 is a cross-sectional view showing an example of a conventional etching apparatus. (1)...Vacuum container, (2)...High frequency electrode, (3
)...Grounding electrode, (10)...Bellows, (11)
...Quartz outer cylinder, (12)...Quartz inner cylinder. In each figure, the same reference numerals indicate the same or corresponding parts. Diagram

Claims (1)

[Claims] A pair of first and second oppositely provided in the vacuum container.
a drive device that moves the first electrode in order to change the distance between the electrode and the second electrode, which is connected to the first electrode, and a vacuum between the vacuum container and the first electrode. In an etching apparatus equipped with an expansion joint provided with a sealing property between a container and a first electrode, a reaction product of an active species and a material to be etched is formed around the expansion joint at the expansion joint. An etching apparatus characterized by being provided with an adhesion prevention body that prevents adhesion.