JPS627271B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dry etching apparatus that etches a sample using electric discharge between opposing electrodes.

Conventionally, in the etching process of semiconductor devices, instead of wet etching using acid, dry etching has been frequently used because it can improve the degree of pattern integration and solve the problem of drainage treatment. . In this dry etching, a discharge is generated between electrodes placed facing each other in a vacuum chamber, and gas plasma in this discharge space is utilized.The sample to be etched is placed on one of the facing electrodes. The etching device is configured so that it can be placed on or adjacent to the etching device. Therefore, in order to increase the etching throughput, it is necessary to increase the area of the electrode on which the sample to be etched is placed, which inevitably leads to an increase in the size of the apparatus.

SUMMARY OF THE INVENTION An object of the present invention is to provide a highly economical dry etching apparatus which eliminates the above-mentioned drawbacks and is capable of increasing the throughput of samples even in a small vacuum chamber.

According to the present invention, in a dry etching apparatus that etches the surface of a sample by generating a discharge between electrodes arranged in a vacuum atmosphere, the first electrode to which a high frequency voltage other than a ground potential is applied is used to hold the sample to be etched. and a second electrode that applies a high frequency that is not at a ground potential to hold the sample to be etched, and between the first electrode and the second electrode, each of the two surfaces is connected to the first electrode. A dry etching apparatus is obtained in which one counter electrode is disposed to face the electrode and the second electrode, respectively. Furthermore, in the dry etching apparatus described above, there is obtained a dry etching apparatus characterized in that the counter electrode is placed at ground potential.

Next, an embodiment of the present invention will be described with reference to FIG. 1, whose configuration is seen transparently from the side. are placed facing each other, and a plate-shaped counter electrode 3 is placed in parallel in the middle between them. A high frequency power source 4, both of whose high frequency output ends are not at ground potential, is connected to the high frequency application electrodes 2a and 2b via both terminals, and the counter electrode 3 is connected to the ground and grounded. placed at a potential.
In addition, the exhaust device 5 is used to evacuate the vacuum chamber 1, and the mass flow controller 6 is used to feed a reaction gas into the vacuum chamber 1.
Note that samples 7a and 7b to be etched are held in the high frequency application electrodes 2a and 2b, respectively.

According to this embodiment, the high frequency application electrodes 2a and 2
The electric field in the space sandwiched by b is symmetrical on the upper and lower surfaces of the counter electrode 3, and the samples 7a and 7b to be etched, which are held by the high frequency application electrodes 2a and 2b, respectively, are under the same conditions. Etched. That is, the samples 7a and 7b to be etched are etched by the impact of ions in the plasma generated by the discharge and the reaction with the reactive gas dissociated in the plasma.

In the above embodiment, the counter electrode 3 is placed at the ground potential, but by connecting the variable voltage DC power supply 8 to the counter electrode 3, an arbitrary potential can be applied. You can also do that. By adjusting the potential of the counter electrode 3 with this power source 8, the counter electrode 3 and the high frequency application electrode 2a,
As a result of being able to control the potential of the plasma generated between the samples 7a and 2b,
The energy of the ions incident on the sample 7b can be controlled, and anisotropic etching can be performed without damaging the photoresist coated on the sample surface.

As is clear from the above description, according to the present invention, by arranging the counter electrode in the middle of two opposing high-frequency applying electrodes that are not at ground potential, an electric field is generated between the counter electrodes. It becomes symmetrical, and 2
The sample to be etched held on each of the two high-frequency application electrodes can be etched under the same conditions, and the throughput of the sample can be reduced by 2 times compared to the case of one high-frequency application electrode using the conventional technology.
Since it can be doubled, the effect of improving processing capacity and economic efficiency is great.

[Brief explanation of the drawing]

FIG. 1 is a side view perspectively showing the configuration of an embodiment of the present invention. In the figure, 1 is a vacuum chamber, 2
Reference numerals a and 2b designate high frequency application electrodes, 3 a counter electrode, 4 a high frequency power source, 5 an exhaust device, 6 a mass flow controller, 7a and 7b a sample to be etched, and 8 a variable voltage DC power source.

Claims (1)

[Claims] 1. In a dry etching device that etches the surface of a sample by generating a discharge between electrodes arranged in a vacuum atmosphere, a first device that applies a high frequency that is not at a ground potential to hold the sample to be etched is used. an electrode, and a second electrode that applies a high frequency that is not at a ground potential to hold a sample to be etched, and between the first electrode and the second electrode, each of the two surfaces is connected to the first electrode. A dry etching apparatus characterized in that one counter electrode is disposed so as to face the second electrode and the second electrode, respectively. 2. A dry etching apparatus according to claim 1, wherein the counter electrode is placed at ground potential. 3. A dry etching apparatus according to claim 1, wherein the counter electrode is connected to a variable voltage power source.