Plasma processing method and resist pattern modifying method

Abstract

The invention provides a plasma processing method and a modifying method of a resist pattern, which is capable of synchronously realizing excellent etching selectivity and shape performance in the process of etching fine holes with high aspect ratio on an oxidation film. The method comprises the following steps: a step of moving the oxidation film, a hard mask layer and the patterned base plate ofa photoresist, which are formed with etched objects in sequence, to a processing container (10) and loading on a lower electrode; a step of supplying a processing gas containing CxFy (wherein x is aninteger less than 3 and y is an integer less than 8), C4F8, rare gas and O2 to the processing container (10); a step of exerting a high-frequency power on an upper electrode (34) from a first high-frequency exerting unit (48) for generation of the plasmas of the processing gas; a step of exerting a high-frequency power for bias voltage on a lower electrode (16) from a second high-frequency powerexerting unit (90); and a step of exerting a direct current voltage on the upper electrode (34) from a direct current voltage exerting unit (50).

Description

technical field [0001] The present invention relates to a plasma treatment method for etching and trimming a fine resist pattern for plasma etching by using plasma and a resist pattern modifying method for modifying the resist pattern before trimming. Background technique [0002] In the manufacturing process of a semiconductor device, a photoresist pattern is formed by a photolithography process on a semiconductor wafer as a substrate to be processed, and etching is performed using this as a mask. [0003] Recently, semiconductor devices have become more and more finer, and fine processing is also required in etching. In response to this refinement, the thickness of the photoresist used as a mask has become thinner, and the photoresist used The photoresist is also gradually changed from KrF resist (that is, the photoresist exposed under the laser light with KrF gas as the light source) to the ArF resist that can form the pattern opening of about 0.13 μm or less (that is, in...

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Problems solved by technology

[0005] However, in the case of forming a fine resist pattern by such trimming, pattern destruction may occur after trimming

In particular, ArF resist is originally a substance for forming fine patterns, and its strength is low, so pattern destruction is more likely to occur

In addition, there is also a problem that the amount of etching in the vertical direction increases during trimming, and the thickness of the remaining resist becomes small.

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