Dry etching method
First Claim
1. A dry etching method for etching a layer of a material using a resist pattern having an inclined sidewall section formed by a pattern width decreased from a top surface towards a bottom surface along a film thickness of the pattern, comprising:
- forming discharge reaction products and allowing the discharge reaction products to be deposited on said inclined sidewall surface for shaping said sidewall section of the mask so that said sidewall section will be substantially perpendicular to said layer, andsubsequently plasma etching said layer.
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Accused Products
Abstract
A method for effecting anisotropic etching of a layer of a material without producing dimensional loss even if the photoresist is of a reverse tapered cross-sectional profile is proposed. A photoresist produced from a chemical amplification negative type photoresist tends to be of a reversely tapered cross-sectional profile after development due to its sensitization properties. According to the present invention, discharge reaction products yielded in a plasma are deposited on an inclined sidewall surface of a photoresist pattern for trimming or shaping the sidewall surface so that the sidewall surface will be substantially vertical. For example, Six Ny, Six Ny Clz, etc. may be deposited from a SiCl4 /N2 mixed gas, sulfur may be deposited from a mixed gas of S2 F2 /H2 S and a carbonaceous polymer may be deposited from a C2 Cl3 F3 gas. Such profile correction may be effected before etching the layer, or simultaneously with the etching under conditions in which the deposition process occurs competitively with the etching process. According to the present invention, dimensional loss may be prevented effectively from occurring during the etching of a layer of an Si-based material or an Al-based material in which the radical mode is a prevailing etching mode.
20 Citations
8 Claims
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1. A dry etching method for etching a layer of a material using a resist pattern having an inclined sidewall section formed by a pattern width decreased from a top surface towards a bottom surface along a film thickness of the pattern, comprising:
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forming discharge reaction products and allowing the discharge reaction products to be deposited on said inclined sidewall surface for shaping said sidewall section of the mask so that said sidewall section will be substantially perpendicular to said layer, and subsequently plasma etching said layer. - View Dependent Claims (2, 3, 4)
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5. A dry etching method for etching a layer of a material using a resist pattern having an inclined sidewall section formed by a pattern width decreased from a top surface towards a bottom surface along a film thickness of the pattern, comprising:
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forming discharge reaction products and allowing the discharge reaction products to be deposited on said inclined sidewall surface for shaping said sidewall section of the mask so that said sidewall section will be substantially perpendicular to said layer, and simultaneously plasma etching said layer. - View Dependent Claims (6, 7, 8)
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Specification