JPS6026295B2 - Spatsuta etching method and container used therefor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of sputter etching silicon oxide parts and a container used therein.

Since sputter etching has unique features not found in other etching methods such as chemical etching, it has recently come to be widely used in fields such as the semiconductor industry.

In sputter etching, there are problems caused by the plasma and its handling.

Among these, the most problematic problem in the past is that various constituent materials placed around the plasma circulate and mix into the plasma, which contaminates the sample. Therefore, a commonly used means to prevent this contamination is to place a plate made of sputter etching resistant material with approximately the same size and shape as the target electrode on the target electrode, and place the sample to be sputter etched on this slope. The purpose is to arrange the following.

The disadvantage of this method is that the temperature of the sample to be sputter etched cannot be sufficiently controlled.

This is a problem when heating is required, but it cannot be ignored when cooling is required, and especially when using a resist mask, such as when performing local selective etching with a predetermined mask pattern. is important. Appropriate cooling is necessary to prevent the mask pattern from loosening, burning, or becoming difficult to peel off, and when the sample is a semiconductor device, to prevent characteristic deterioration due to localized temperature rises. Temperature control is an important requirement.

The method of arranging a plate of sputter etching resistant material on the target electrode is attracting attention from the viewpoint of preventing contamination as well.

That is, it has become known that the sputter etching rate changes depending on the quality of the sputter etching resistant material. Currently, if the sample part to be sputter-etched is silicon oxide and there is silicon on the sample as a part that is not desired to be sputter-etched, polytetrafluoroethylene and other materials are used as sputter-etching resistant materials. It is said that it is best to select a fluororesin and select a fluorocarbon such as Freon-14 (CF4) as the introduced gas. This makes it possible to increase the etching rate of the silicon oxide portion without damaging the silicon portion on the sample. The object of this invention is to make it possible to sufficiently control temperature while increasing the effect of preventing contamination, and to increase only the etching rate of silicon oxide. The sputter etching method of the present invention includes:
The method is characterized in that a sample having a silicon oxide portion to be sputter-etched is placed on a target electrode, and the sample is further surrounded by a polypropylene wall provided with a window, and sputter-etched. .

Further, according to the present invention, as a means for enclosing the sample with a polypropylene wall provided with a window, a polypropylene cylindrical body with a window bored in the side surface and a polypropylene wall with a wall sufficient to cover one end of the cylindrical body are used. To provide a combination container-like container comprising a lid-like body made of polypropylene, or a container in which the cylindrical body and the diamond-shaped body are integrated. Hereinafter, the present invention will be explained using an example of the implementation of the present invention. For convenience of explanation, the structure around the target electrode of a sputter etching apparatus including an example of the container of the present invention will be explained first, and then an example of the effects of the present invention will be explained. do.

FIG. 1 is a schematic assembly diagram showing the structure around a target electrode of a sputter etching apparatus.

3 in the figure is a cylindrical body made of polypropylene according to the present invention, and 4 is a window bored therein. It is a lid-like body made of polypropylene that fits 2 and 3 together.

10 is a target electrode, and the sample 9 is placed directly on the target electrode.

Reference numeral 5 denotes a polypropylene plate that covers the target electrodes other than those on which the containers 3 and 4 of the present invention are arranged, and further enhances the contamination prevention effect.

1 is a counter electrode, 8 is a guide, and 6 is a guide hole.

FIG. 2 shows a partially cut-out view of the device shown in FIG. 1 after it has been set.

Now, with these preparations, we used Pron-14 as the introduced gas and changed the RF power to determine the etching speed of the silicon oxide portion on sample 9 (the rest of the surface was made of silicon). The measurement results are shown in Figure 3.

The data 31 in the figure is as follows in FIG. 1 and FIG.
This is the result when all of 2, 3, 4, and 5 are made of polypropylene, and compared with the result 32 when all of them are made of polytetrafluorethylene and the result 33 when all of them are made of quartz. It will be seen how outstanding the effects of the polypropylene discovered and employed in the present invention are. The remaining data 34 shown in the figure also uses polypropylene, but instead of surrounding the sample with a polypropylene wall with windows as in the present invention, it was placed on the target electrode. This is obtained by simply placing a polypropylene sheet and placing the sample on this sheet.

By comparing data 31 and data 34, it will be seen how outstanding the effects of the present invention are. In the present invention, the material of the container is limited to polypropylene, but even if this is replaced with a fluororesin such as polytetrafluorethylene or a wide range of resins containing a large amount of carbon and hydrogen, the scope of the present invention still applies. Of course, it is not something that exceeds the above, but merely something that is attempted to be avoided.

[Brief explanation of the drawing]

FIGS. 1 and 2 are views showing the structure around the target electrode of an example of an apparatus implementing the method of the present invention, together with an embodiment of the container of the present invention. In the figure, 1 is a counter electrode, 10 is a target electrode, 9 is a sample having a silicon oxide portion to be sputter etched, and 3 is a polypropylene cylindrical body according to the present invention.
4 indicates a window drilled in 3, and 2 indicates a lid-shaped body made of polypropylene according to the present invention. FIG. 3 is for explaining one of the effects of the present invention, the effect on the etching speed of silicon oxide.
The result is 31 when 3, 4, and 5 are all made of polypropylene, 32 when they are all made of polytetrafluorethylene, and 33 when they are all made of quartz. Data 34 is data obtained by merely implementing a conventional method using polypropylene in which a simple sheet of polypropylene is placed on the target electrode and a sample is placed on the sheet. Freon 14 was used as the introduced gas. 1 spear, 2 spears, 5 spears

Claims (1)

[Scope of Claims] 1. A sample having a silicon oxide portion to be sputter etched is placed on a target electrode, and the sample is further surrounded by a polypropylene wall provided with a window to perform sputter etching. A spatuta etching method characterized by: 2 A combination container-like structure consisting of a polypropylene cylindrical body with a window bored on its side and a polypropylene lid-shaped body having a shape sufficient to cover one end of the cylindrical body, or the cylindrical body and the lid-shaped body. A sputter etching container used to enclose a sample.