JPS6248758B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an upper water-cooled electrode type dry etching apparatus that is applied to dry etching processing of semiconductor substrates, photomask substrates, etc., and its purpose is to enhance the water cooling effect of the substrate to be etched. The objective is to reduce damage to photoresist images, reduce the influence of dust, etc., and improve processing accuracy and work efficiency.

Conventionally, a substrate to be etched (Fig. 1), such as a semiconductor substrate or a photomask substrate, is generally placed on the electrode with the water-cooled electrode plate facing downward, and the etched surface thereof facing upward. However, although this method does not require a particular substrate support mechanism and is easy to use in terms of equipment, it also has the following drawbacks. In other words, the adhesion between the substrate to be etched and the surface of the water-cooled electrode plate is not good, and the water-cooling effect of the substrate to be etched is insufficient, so the temperature of the substrate increases during the etching process, causing the photoresist formed on the substrate to deteriorate. The image is damaged, resulting in reduced processing accuracy.

In order to enhance the etching effect, applying grease or the like to the back of the substrate and fixing it on the water-cooled electrode plate improves the water-cooling effect, but it does not prevent contamination of the substrate to be etched or others from the grease. .

Since the etched surface is placed on the lower water-cooled electrode plate with the surface to be etched facing upward, it is difficult to prevent dust from adhering to the surface of the etched substrate during installation or vacuum evacuation, resulting in many defects in the etched product. Sometimes.

In order to improve the above points, there are already dry etching apparatuses in which a water-cooled electrode plate is installed on the top, one of which is shown in Figure 2. This is a method in which the upper water-cooled electrode plate is fixed with a clamp, etc.
Although the adhesion between the two is good, it requires two steps: attaching the substrate to be etched to the substrate mount, and holding the substrate mount under the upper water-cooled electrode plate with a clamp. Besides the loss of efficiency,
Since the number of steps increases, the influence of adhesion of dust and the like is correspondingly large.

In addition, in the system shown in Fig. 3, the substrate mount is lifted up with a support through a hole in the upper water-cooled electrode plate and brought into close contact with the electrode plate.
It is necessary to drill through holes in the upper water-cooled electrode plate, and the device becomes complicated.

In FIG. 1 described above, reference numeral 1 is a lower water-cooled electrode plate, 3 is a substrate to be etched, 5 is a counter electrode plate, 6 is an insulator, and 7 is a high frequency power source. In FIG. 2, 1 is an upper water-cooled electrode plate, 2 is a substrate mounting stand, 3 is a substrate to be etched, 4 is a clamp member,
6 is an insulator; in FIG. 3, 1 is an upper water-cooled electrode plate, 2 is a substrate mount, 3 is a substrate to be etched, 4 is a support, and 6 is an insulator.

The present invention is a further improvement of the dry etching apparatus using a water-cooled electrode plate on the upper part as shown in FIGS. 2 and 3.

In other words, with a simple device, it is possible to enhance the water cooling effect of the etched substrate, reduce damage to the photoresist image, and reduce the influence of dust, etc., making it possible to perform highly accurate etching processing and improve work efficiency. It is something.

This will be explained with reference to FIGS. 4A, 4B, and 3C of the embodiment.

In the processing chamber 10, the substrate mounting table 11 for the substrate to be etched 12 is provided with support columns 13, 1 protruding from below.
3, it is installed vertically movably via springs 15, 15 in the branch pipes 14, 14 planted in the bottom panel, and the branch pipe 1 is located below the board mount 11.
A counter electrode plate 16 is disposed between the counter electrode plates 4 and 14, and a gas injection pipe 17 is disposed horizontally above the counter electrode plate 16. The upper part of the processing chamber 10 is open, and an exhaust pipe 18 is provided on the side wall thereof. The upper water-cooled electrode plate 19 that fits into the upper opening end of the processing chamber 10 is connected to the cover 20.
It is installed so that it can be moved up and down by a lift 21 located outside the processing chamber 10.
The upper water-cooled electrode plate 19 has an insulator portion 22 on its outer periphery.
It fits into the processing chamber 10, and there is a cooling water pipe 23 inside.
is provided and connected to a high frequency power source 24.

When in use, raise the upper water-cooled electrode plate 19 upwards using the lift 21 as shown in Fig.
After mounting the substrate 12 to be etched on the substrate mounting table 11 with its etching surface facing downward, the upper water-cooled electrode plate 19 is lowered by the lift 21 as shown in Figure C, and the electrode plate 19 is placed in the processing chamber. At the same time, the spring 1
5 and 15, the cover 20 descends until it hits the upper opening end of the processing chamber 10. Here, the substrate 12 to be etched on the substrate mount 11 is brought into close contact with the lower surface of the electrode plate 19 while being balanced by the repulsive action of the springs 15, 15.

As explained above, in the present invention, the water-cooled electrode plate is provided above so as to be movable up and down, and the substrate mount for attaching the substrate to be etched is provided so as to be movable up and down via a spring. As it descends, when it comes into contact with the substrate to be etched mounted on the substrate mount, due to the repulsive action of the spring supporting the substrate mount, the two are balanced and come into close contact with each other. Since the substrate to be etched is thus well cooled, the photoresist image formed on the substrate is not distorted or damaged by heat. Moreover, since the substrate to be etched is mounted on the substrate mount with its etching surface facing downward, there is very little dust, etc. adhering to it, and good cooling prevents distortion of the photoresist image. Machining accuracy can be improved. Furthermore, even though the machining accuracy is high, the work efficiency can be increased because the machining can be done by moving the upper water-cooled electrode plate up and down.

According to experiments, the temperature of the substrate to be etched is 100 to 200°C in the conventional dry etching apparatus of the lower water-cooled electrode type, whereas that of the upper water-cooled electrode type of the present invention is 30 to 80°C. The temperature is low.

[Brief explanation of the drawing]

FIG. 1 is a simplified explanatory diagram of a conventional lower water-cooled electrode type dry etching apparatus, FIGS. 2 and 3 are simplified explanatory diagrams of an upper water-cooled electrode type dry etching apparatus different from the present invention, and FIG. A, B, and C are explanatory cross-sectional views of an upper water-cooled electrode type dry etching apparatus of the present invention. Code, 10...processing room, 11...board mounting stand,
12...Substrate to be etched, 13...Strut, 14
... Branch pipe, 15 ... Spring, 16 ... Counter electrode plate, 17 ... Gas injection pipe, 18 ... Exhaust pipe, 1
9... Upper water-cooled electrode plate, 21... Lift, 22...
...Insulator, 23...Cooling water pipe, 24...High frequency power supply.

Claims (1)

[Claims] 1. A substrate mounting stand on which a substrate to be etched, such as a semiconductor substrate or a photomask substrate, can be mounted with its etching surface facing downward, is supported by a vertically movable support device using a spring, etc. An upper water-cooled electrode type dry etching device characterized in that an upper water-cooled electrode plate is provided above the mounting base and is movable up and down.