Plasma processing device and plasma processing method

Abstract

That surface of an electrode plate 20 which is opposite to a susceptor 10 has a projection shape. The electrode plate 20 is fitted in an opening 26a of shield ring 26 at a projection 20a. At this time, the thickness of the projection 20a is approximately the same as the thickness of the shield ring 26. Accordingly, the electrode plate 20 and the shield ring 26 form substantially the same plane. The major surface of the projection 20a has a diameter 1.2 to 1.5 times the diameter of a wafer W. The electrode plate 20 is formed of, for example, SiC.

Description

[0001] The present invention relates to a plasma process system and a plasma process method which perform processes, such as film deposition and etching, using a plasma.[0002] A plasma process system which processes the surface of a substrate, such as a semiconductor wafer, using a plasma is used in a fabrication process for a liquid crystal display or the like. As plasma process systems, there are, for example, a plasma etching system which performs etching on a substrate and a plasma CVD system which performs chemical vapor deposition (Chemical Vapor Deposition: CVD). Of them, a parallel plate plasma process system is widely used because it has an excellent process uniformity and its system structure is relatively simple.[0003] The structure of a parallel plate plasma process system is shown in FIG. 17. As shown in FIG. 17, a plasma process system 101 comprises a chamber 102, a shower electrode 103 which feeds a process gas into the chamber 102 and constitutes an upper electrode, ...

AI Technical Summary

Benefits of technology

[0016] It is therefore an object of the invention to provide a plasma process system and a plasma process method which can perform a process with high uniformity on a subject to be processed.

[0079] A focus ring 17 made of an insulator, such as ceramics, is provided at the peripheral portion of the top surface of the susceptor 10. The focus ring 17 has an opening in the center and the diameter of the opening is made slightly larger than that of the wafer W. The wafer W is mounted on the top surface of the susceptor 10 which is exposed to the inside of the opening of the focus ring 17. The focus ring 17 allows a plasma active seed to be effectively incident to the wafer W.

[0084] The screwed portions of the peripheral portion of the electrode plate 20 are covered with a shield ring 26 made of ceramics or the like, such as aluminum nitride. The shield ring 26 has a major surface in which an opening 26a is formed, and is fixed to the side portions or the like of the roof of the chamber 2 in such a way that the major surface becomes approximately parallel to the roof surface of the chamber 2. The opening 26a of the shield ring 26 is formed to have a smaller diameter than the electrode plate 20 and is provided so that the electrode plate 20 is exposed to the inside of the opening 26a. At least the major surface portion of the shield ring 26 is formed in a plate shape having a thickness of about 10 mm. Covering the screwed portions with the shield ring 26 prevents abnormal discharge or the like at the screwed portions at the time of generating a plasma

[0088] In the above-described structure, the electrode plate 20 and the shield ring 26 form a flat surface with respect to a plasma generation area. In this case, a step is not formed between the exposed surface of the electrode plate 20 and the major surface of the shield ring 26. Accordingly, the flow of the process gas which is sprayed though the gas holes 19 is not disturbed at such a step portion and the flow of the process gas which is sprayed through the entire gas holes 19 becomes nearly uniform. This allows the process gas to be supplied to the surface of the wafer W with high uniformity so that a process with high uniformity is performed on the wafer W.

Problems solved by technology

This makes the gas supply at the center portion and end portion of the to-be-processed subject W uneven, thus lowering the process uniformity.

Therefore, a process with a sufficiently high uniformity may not be executed.

It is therefore difficult to optimize the gas blowoff diameter and the upper electrode diameter by independently varying them to thereby improve the process uniformity.

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