Plasma processing apparatus

Abstract

To make it possible to suppress deterioration of processing properties of a sample to be processed due to the distortion of ion sheath at the end portion of the sample to be processed or possible to maintain the condition for suppressing the deterioration, so that the acquisition rate of acceptable products can be increased, so as to thereby improve the yield. In a plasma processing apparatus, a minute hole 10 is provided in a focus ring 9 in the vicinity of the inner circumferential portion thereof. Current detecting means 11 is arranged in the bottom portion of the minute hole 10. A high-frequency power is supplied to the focus ring 9 via high-frequency power distributing means 16. A state of distortion of an ion sheath 18 is detected from an amount of current which is changed according to the amount of the high-frequency power supplied to the focus ring 9 and which is detected by current detecting means 11. Further, the amount of high-frequency power supplied to the focus ring 9 is controlled by a control section 21 so as to correct the detected distortion state.

Description

[0001]The present application is based on and claims priority of Japanese patent application No. 2008-181287 filed on Jul. 11, 2008, the entire contents of which are hereby incorporated by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a semiconductor manufacturing apparatus for manufacturing a semiconductor device. More particularly, the present invention relates to a plasma processing apparatus using a dry etching technique for etching, by using the plasma, semiconductor materials, such as silicon and a silicon oxide film, according to a mask pattern shape formed of a resist material, and the like.[0004]2. Description of the Related Art[0005]The dry etching is a semiconductor fine processing method in which process gases are introduced into a vacuum chamber having vacuum evacuation means, so as to be converted into plasma by electromagnetic waves, and in which the surface of a sample to be processed other than a masked po...

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Benefits of technology

[0011]For example, it is possible to minimize the influence of the tilting due to the distortion of the plasma sheath, which is caused at the wafer end portion, and possible to maintain the processing properties in the wafer end portion for a long time, in such a manner that the distortion of plasma sheath caused by the wear of the focus ring is monitored by the current detecting means, and that the ratio of amounts of high-frequency power applied to the focus ring and the wafer is controlled by controlling the amount of high-frequency power supplied to the focus ring according to the monitored distortion amount.

[0012]Further, in the above description, there is roughly described the effect in the case where the present invention is applied to suppressing the time-based change due to the wear of the focus ring. However, the present invention can also be used to optimize the processing properties in the wafer edge portion in the case of a different object to be processed and a different processing condition. Thereby, even for various objects to be processed and various processing conditions, the optimization can be easily performed so as to obtain a state in which the wafer edge portion can always be processed with high accuracy.

Problems solved by technology

As a result, it becomes impossible to maintain the required processing accuracy in the wafer edge portion due to a phenomenon referred to as “tilting” in which a shape desired to be processed perpendicularly to the wafer surface is formed into a shape distorted in the direction of the plasma sheath.

However, in the conventional method, there is a problem that it is difficult to maintain the long-term stability and processing properties of the wafer edge portion for each of different plasma processing conditions, because the degree of tilting is changed due to a time-based shape change of the focus ring according to the wear thereof, and due to a difference in the plasma processing conditions.

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