Plasma processing apparatus and method

Abstract

To improve processing uniformity by improving a working characteristic in an edge exclusion region. Provided is a plasma processing apparatus for processing a sample by generating plasma in a vacuum vessel to which a processing gas is supplied and that is exhausted to a predetermined pressure and by applying a radio frequency bias to a sample placed in the vacuum vessel, wherein a conductive radio frequency ring to which a radio frequency bias power is applied is arranged in a stepped part formed outside a convex part of the sample stage on which the wafer is mounted, and a dielectric cover ring is provided in the stepped part, covering the radio frequency ring, the cover ring substantially blocks penetration of the radio frequency power to the plasma from the radio frequency ring, and the radio frequency ring top surface is set higher than a wafer top surface.

Description

CLAIM OF PRIORITY[0001]The present application claims priority from Japanese patent application JP 2012-152005 filed on Jul. 6, 2012, the content of which is hereby incorporated by reference into this application.FIELD OF THE INVENTION[0002]The present invention relates to a plasma processing apparatus and a processing method for processing a sample, and more specifically, to a plasma processing apparatus for processing a sample while applying a radio frequency bias to the sample in an etching processing of the sample using plasma.BACKGROUND OF THE INVENTION[0003]Generally, dry etching using plasma is performed in a semiconductor manufacturing process. The plasma processing apparatus for performing dry etching uses various systems.[0004]On the other hand, with an improvement in integration degree of the recent semiconductor devices, improvement of micro fabrication, i.e., working accuracy is required, and at the same time, improvement of in-wafer uniformity of an etching rate or in-...

AI Technical Summary

Benefits of technology

The present invention is about a plasma processing apparatus and its method that can improve the uniformity of fine processing performance and enhance the etching performance of the edge exclusion region. This is achieved by using a cover ring made of dielectric material having plasma resistance, which reduces the area of the sample stage in direct contact with the plasma and prevents damage to the electrode surface caused by the plasma. The cover ring acts as a capacity component to the radio frequency bias applied to the sample stage, reducing its impedance and improving its performance.

Problems solved by technology

However, there is a case where the material is limited in consideration of an etching process, and even if the shape is the optimum, in some cases, the applied radio frequency bias power cannot transfer the cover ring that is formed a certain finite thickness, that is, the electric power for bias supplied to the cover ring and the plasma cannot couple with each other, and it may be impossible to form an expected plasma ion sheath on the top surface of the cover ring, namely, to form the plasma ion sheath having the same thickness as that of the plasma ion sheath on the wafer surface.

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