JPS6012735A - Etching device - Google Patents

Abstract

PURPOSE:To enable easy setting of a highly accurate and uniform interval even through it is extremely small by installing a spacer on one of a pair of parallel plate electrodes and regulating the interval between the both electrodes with the spacer. CONSTITUTION:In a chamber 1, an upper electrode 4 and a lower electrode 5 which are a pair of plate electrodes placed face to face in parallel are installed. The electrode 4 is fixed on the chamber 1 with a support axis 6 and on the circumference of the electrode 4, e.g., a ring wall 7 which constitutes a spacer is fixed downwards. The electrode 5 is supported by a suppoting axis 10 and on the upper surface center of the electrode, an object 11 to be etched can be loaded. At the lower end of the support axis 10 outside of the chamber 1, an up-and-down movement mechanism 12 is also provided whereby the support axis 10 and the electrode 5 can be moved vertically. In this construction, the electrode 5 is moved vertically by the operation of the mechanism 12 and stopped when the lower end of the spacer 7 touches the upper surface circumference of the electrode 5. In this way, the electrodes 4 and 5 are set with a uniform interval equal to the height l of the spacer 7 face to face each other.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an etching apparatus, and more particularly to a parallel plate electrode type etching apparatus.

[Background technology]

In the manufacturing process of semiconductor devices, dry etching technology is indispensable to 1% of etching technology, and various etching devices have been proposed (for example, JP-A-51-79650).
Publication No.). Among them, a parallel plate electrode type etching apparatus in which a pair of flat plate electrodes are disposed facing each other is frequently used because it has a simple structure and can obtain good etching effects. That is, in this type of etching apparatus, flat plate electrodes (upper electrode, lower electrode) arranged one above the other are set at a predetermined interval, and a wafer to be etched is placed on one of the electrodes 5, for example, the lower electrode. Etching is carried out by applying high-frequency power between the two electrodes while keeping it in a required gas atmosphere.

By the way, in this type of etching apparatus, the upper and lower electrodes are usually 19.5 mm in diameter depending on the material to be etched. xtg, but since the lateral dimension of each electrode is extremely large compared to this spacing, it is necessary to ensure the spacing with high precision over the entire electrode surface, that is, to ensure the parallelism of both electrodes with high precision. It is difficult to publish it. For this reason, the inventors have found that minute variations in the spacing hinder uniform etching on the wafer surface, causing variations in the characteristics of semiconductor devices.

In addition, with this method, a cover is provided that covers both electrodes and the entire inner surface of the chamber to prevent contaminants scattered from the inner surface of the chamber from adhering to the surface, but the shape of the cover becomes complicated and It has been found that the structure and manufacture of the etching apparatus are difficult, as the entire structure becomes large.

[Purpose of the invention]

An object of the present invention is to provide an etching technique that allows the spacing between parallel plate electrodes to be set uniformly and with high precision. Another object of the present invention is to provide an etching technique that can simplify the structure by eliminating the need to provide a separate cover.

The above and other objects and novel features of the present invention are as follows:
Based on the description of this specification and the accompanying drawings [Summary of the Invention] Representative inventions disclosed in this application will be briefly summarized as follows.

In other words, one of the parallel plate electrodes is made movable and a spacer is extended around either of the plate electrodes so that it can collide with the other plate electrode.The spacer makes the distance between both electrodes uniform. In addition, the spacer and both electrodes form a cover that covers the object to be etched to prevent contamination, thereby simplifying the structure of the etching apparatus and improving etching accuracy.

〔,Example〕

FIG. 1 is a sectional view of an embodiment in which the present invention is applied to a plasma etching apparatus. In the figure, 'C1' is a chamber, which is provided with a gas supply port 2 that supplies processing gas to the upper electrode, which will be described later, and an exhaust port 3 that maintains the required vacuum pressure in the chamber 1 at the bottom. 3 is connected to a vacuum pump (not shown).

On the other hand, inside the chamber 1 are provided an upper electrode 4 and a lower electrode 5, each of which is a pair of flat plate electrodes arranged vertically and facing each other in parallel. The upper electrode 4 is fixed to the chamber 1 by a support shaft 6 passing through the upper part of the chamber 1, and its position is fixedly determined.

Further, for example, an annular wall 7 is fixed downwardly around the upper electrode 4, and is configured as a spacer. That is, the spacer 7 has a required height l and is removably fixed by a set screw 8 or the like, and its lower edge can abut against the upper surface periphery of the lower electrode 5, as will be described later. The spacer 7 is made of aluminum oxide, fluororesin, or the like. Further, a high frequency power source 9 is connected to the upper electrode 4, and the gas supply port 2 is formed to pass through the support shaft 6.

The lower electrode 5 has a support shaft 10 passing through the lower part of the chamber 1.
A wafer 11 as an object to be etched can be placed at the center of the upper surface.

A vertical movement mechanism 12, exemplified by a rack and pinion mechanism, is attached to the lower end of the support shaft 10 outside the channel 1, and rotation of the pinion 13 moves the rack 14 and the support shaft 10 integral therewith. The lower electrode 5 can be moved up and down.

According to the above configuration, the wafer 1 onto the lower voltage wZ, 5
No particular problem will arise as long as the loading and unloading of the vehicle is carried out with the lower cab 5 moved downward as shown in the figure. Wow 1
1 is placed, the vertical movement mechanism 12 is operated to move the lower electrode 5 upward, and the spacer 7 is stopped when the lower edge of the spacer 7 collides with the peripheral portion of the upper surface of the lower electrode 5. As a result, as shown in FIG. 2, the height of the upper electrode 4 and lower electrode 5 is equal to that of the spacer 7! They will face each other with an interval dimension equivalent to .

Moreover, both the electrodes 4.5 and the spacer 7 surround the entire wafer S11.

Therefore, one electrode 4.5 has a spacer 7 at its periphery.
Since the facing distance is regulated by , the parallelism between both electrodes 4 and 5 is made good to make the distance uniform.

It can be easily achieved. As a result, by creating a gas atmosphere with a predetermined degree of vacuum inside the spacer 7 and further inside the chamber 1 through the exhaust port 3a and applying high frequency power between both electrodes 4.5, plasma is generated uniformly between both electrodes.
The entire surface of the wafer 11 can be etched uniformly. On the other hand, during etching, contaminants scattered from the inner surface of the chamber 1 are prevented from entering between the electrodes 4 and 5 by the spacer 7, so that they do not adhere to the surface of the wafer 11 (to prevent contamination of the wafer). It can be prevented.

As a result, good etching can be achieved and the yield can be improved.

If it is necessary to change the distance between the electrodes 4.5 due to a difference in the material to be etched, the set screw 8 may be used to replace the spacer with a spacer having a different height.

〔effect〕

(1) A spacer is provided on one side of a pair of parallel plate electrodes, and this spacer regulates the distance between both electrodes, so
Even when the spacing is minute, it is possible to easily set the spacing to be highly accurate and uniform, and the etching accuracy can be improved.

(2) By making the spacer into an annular or angular shape,
Since the spacer and both electrodes can cover the entire object to be etched, it is possible to prevent contaminants generated within the chamber from adhering to the object to be etched, and it is not necessary to cover the entire inner surface of the chamber, simplifying the configuration. can be achieved.

(3) By making the spacer replaceable and replacing it with a spacer having a different height dimension, the distance between both electrodes can be changed very easily depending on the spacer.

Although the invention made by the present inventor has been specifically explained based on examples, it is understood that the present invention is not limited to the above-mentioned examples, and that various changes can be made without departing from the gist of the invention. Needless to say, for example, the spacer may be provided on the lower electrode, or the spacer may be provided on the upper and lower electrodes, and the spacing may be regulated by the sum of the heights of both spacers (
・. Also.

You can also move the upper electrode up and down (・.

[Application field]

In the above explanation, the invention made by the present inventor was mainly applied to a plasma etching apparatus, which is the background field of application. Can be applied to all busy schedules.

[Brief explanation of the drawing]

1 is a sectional view of an apparatus according to an embodiment of the present invention, and FIG. 2 is a sectional view illustrating its operation. 1...Chamber, 2...Gas supply port, 3, 3a...
・Exhaust port, 4... Upper electrode, 5 Lower electrode, 7...
Spacer, 9... High frequency power supply, 11... Wafer (
(object to be etched), 12... Vertical motive measures. Agent Patent Attorney Akio Takahashi Figure 1

Claims (1)

[Scope of Claims] 1. An etching apparatus equipped with a pair of parallel plate electrodes arranged opposite to each other is constructed such that at least one of the electrodes can be moved in a direction opposite to the other, and 2. An etching apparatus characterized in that a spacer is attached to one electrode facing the other. 2. When both parallel plate electrodes are brought close to each other, the spacer and both electrodes are configured so that the object to be etched can be surrounded. 3. The etching apparatus according to claim 1, wherein the spacer is attached to the electrode so that it can be replaced with a spacer of a different height dimension. Etching equipment.