JPS63177520A - Dry etching device - Google Patents

Abstract

PURPOSE:To prevent a local glow discharge, improve uniformity of an etching speed and prevent a resist from deteriorating by covering an edge part of an electrode on which a substance to be etched is placed with a bulk insulator. CONSTITUTION:An edge part of an electrode 3a on which a substance to be etched is placed is constructed from a structure so that its edge part is covered with a bulk-insulator 8a. Such a configuration avoids a local glow discharge at the above edge part. And it may be as well to make arrangements as follows; the electrode 3b on which the substance to be etched is placed is smaller than its substance and its electrode 3b is not directly exposed to the plasma. And although organic substances of tetrafluoroethylene are used as bulk insulators 8a and 8b, the same effect is obtained when metallic oxides such as Al2O3 and SiO2 are used as the bulk insulators.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is used in the manufacture of electronic components such as semiconductor devices.

Conventional technology In recent years, dry etching equipment has shifted from a batch processing system that processes many items at the same time to a single wafer processing system that processes each item one at a time in order to increase the diameter and size of the objects to be etched and improve the uniformity of etching speed. It's coming. However, in the single wafer processing method, in order to improve the processing capacity, it is necessary to increase the etching speed, which necessarily requires increasing the high frequency power density (high frequency power/electrode area) supplied to the electrode.

An example of the electrode structure of the above-mentioned conventional dry etching apparatus will be described below with reference to the drawings.

FIG. 3 shows the electrode structure of a conventional dry etching device. In FIG. 3, 1 is a vacuum container, 2 is an insulator, 3 is an electrode for placing an object to be etched, 4 is an object to be etched, and 6 is a high frequency power source as means for causing glow discharge. 6 is a gas supply hole connected to gas introducing means (not shown), 7 is an exhaust hole connected to exhaust means (not shown), and 9 is a grounded polar electrode.

The operation of the dry etching apparatus constructed as described above will be explained below. First, the inside of the vacuum chamber 1 is evacuated to 1 mTorr or less by the exhaust means, and then a constant pressure is maintained while introducing a constant flow of gas depending on the object to be etched from the gas supply means.

Thereafter, power is supplied from the high frequency power source 6 to cause glow discharge and generate plasma. The object to be etched is removed by ions and radicals in the plasma.

Problems to be Solved by the Invention However, with the above configuration, the discharge concentrates at the edge portion of the object-to-be-etched electrode 3 during plasma generation due to glow discharge, resulting in non-uniformity in plasma density. , sometimes glow discharges occur locally. Furthermore, even if the surface of the electrode 3 for placing the object to be etched is covered with a metal oxide, etc., the metal oxide, etc. on the edge part of the electrode 3 for placing the object to be etched may become thinner or pinholes may occur due to the above reasons. Since this is easy to occur, metal oxides, etc. may peel off, and glow discharge may occur locally in the pinhole area.

As a result, there have been problems in that the uniformity of the dry etching rate is poor and the resist material used as the mask material is altered.

In view of the above-mentioned problems, the present invention provides a dry etching apparatus that prevents local glow discharge at the edge portion of the electrode 3 for placing an object to be etched, has good etching rate uniformity, and does not cause deterioration of the resist material. It is something to do.

Means for Solving the Problems In order to solve the above problems, the dry etching apparatus of the first aspect of the present invention has a structure in which the edge portion of the electrode for placing the object to be etched is covered with a bulk insulator. It is prepared. A second aspect of the present invention is such that the electrode for placing the object to be etched is smaller than the object to be etched, and the electrode for placing the object to be etched is not directly exposed to plasma.

Operation According to the present invention, by covering the electrode for placing an object to be etched with a bulk insulating material, it is possible to prevent localized glow discharge due to pinholes, which occurs in conventional insulating films.

Alternatively, by making the electrode for placing the object to be etched smaller than the object to be etched, the electrode for placing the object to be etched is not directly exposed to plasma, and local glow discharge can be prevented. Based on the above results,
It is possible to improve the uniformity of etching speed and prevent resist deterioration.

EXAMPLE Hereinafter, a dry etching apparatus according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows the electrode structure of a dry etching apparatus in a first embodiment of the present invention. In Figure 1,
1a to 7a have the same names as 1 to 7 in FIG. 9a is a grounded plate electrode, 8a is a bulk insulator,
Polytetrafluoroethylene was used. The basic operation of the dry etching apparatus constructed as above is as described in the explanation of the conventional example above, but by covering the edge portion of the electrode 3a for placing the object to be etched with a bulk insulator, The present embodiment is characterized in that it is possible to prevent local glow discharge at the edge portion.

A second embodiment of the present invention will be described below with reference to the drawings. FIG. 2 shows the electrode structure of a dry etching apparatus showing a second embodiment of the present invention. In FIG. 2, 1b to 7b have the same names as 1 to 7 in FIG.

9b is a grounded plate-shaped electrode, and 8b is a bulk insulator for protecting the side surface of the electrode 3b for placing the object to be etched from plasma, and polytetrafluoroethylene is used. The basic operation of the dry etching apparatus constructed as above is the same as described in the description of the conventional example above. The feature of this embodiment is that the electrode for placing the object to be etched is made smaller than the object to be etched, and the electrode for placing the object to be etched is configured so that it is not directly exposed to plasma. The present invention is capable of preventing local glow discharge at the edge portions.

Above 1. Regarding the second embodiment, it has been experimentally confirmed that local glow discharge at the edge portion of the electrode for placing the object to be etched is completely prevented.

In addition, 1. In a second embodiment, the bulk insulator 8
Although a and 8b were made of an organic material such as tetrafluoroethylene, similar results were obtained by using a metal oxide such as At203°S s O2 for the bulk insulators 8a and 8b.

Effects of the Invention As described above, the present invention provides a method of covering the edge portion of the electrode for placing the object to be etched in a dry etching apparatus with a bulk insulator or by making the electrode for placing the object to be etched smaller than the object to be etched. By preventing the electrode for placing the object to be etched from being directly exposed to plasma, localized glow discharge at the edge of the electrode for placing the object to be etched is prevented, improving the uniformity of the etching rate, and preventing deterioration of the resist. can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the electrode structure of a dry etching apparatus according to a first embodiment of the present invention, and FIG.
FIG. 3 is a schematic diagram showing the electrode structure of the dry etching apparatus in the embodiment. FIG. 3 is a schematic diagram showing the electrode structure of the conventional dry etching apparatus. 1a, 1b...vacuum container, sa, 3b...
...Electrodes for placing the object to be etched, 4a, 4b...
・Object to be etched, 5a, 5b...High frequency power supply, sa, ab...Bulk insulator, 9a, 9b
・・・・・・Plate electrode. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 3
figure

Claims (4)

[Claims] (1) A plate-like electrode and an electrode for placing an object to be etched, which are arranged to face each other in a vacuum container, a means for supplying gas into the vacuum container, and an exhaust means for keeping the inside of the vacuum container at a constant pressure; In the dry etching apparatus, the object to be etched is removed by generating gas plasma by means of applying high frequency power between the plate-shaped electrode and the electrode for placing the object to be etched and causing a glow discharge of the gas. A dry etching apparatus characterized in that an edge portion of an electrode for placing an etching object is covered with a bulk insulator. (2) The dry etching apparatus according to claim 1, wherein the bulk insulator is a metal oxide. (3) The dry etching apparatus according to claim 1, wherein the bulk insulator is an organic material. (4) a plate-like electrode and an electrode for placing an object to be etched, which are arranged to face each other in a vacuum container, a means for supplying gas into the vacuum container, and an exhaust means for maintaining the inside of the vacuum container at a constant pressure; In the dry etching apparatus, the object to be etched is removed by generating gas plasma by means of applying high frequency power between the plate-shaped electrode and the electrode for placing the object to be etched and causing a glow discharge of the gas. A dry etching apparatus characterized in that an electrode for placing an object to be etched is smaller than an object to be etched, and the electrode for placing an object to be etched is not directly exposed to plasma.