US 4,791,046 AGranted

Process for forming mask patterns of positive type resist material with trimethylsilynitrile

AssigneeOki Electric Industry Co., Ltd.

InventorKen Ogura

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Abstract

A process for forming high resolution resist patterns using a positive type resist material comprising a photoactive resin having phenolic hydroxyl groups, an organic solvent, and 5 to 50% by weight of trimethylsilylnitride. The process for forming high resolution mask patterns comprises the steps of forming a first resist layer on a wafer for planarizing the wafer surface, forming a second resist layer on said first resist layer by using the positive type resist material mentioned above wherein the first resist layer has a higher plasma etch rate than the second resist layer, exposing and removing the second resist layer so as to form a mask pattern, and subjecting the mask pattern and the first resist layer to a reactive ion etching so as to removce the first resist layer by using the mask pattern as an etching mask.

Claims20

Dependent claims

A process for forming mask patterns of positive type resist material with trimethylsilylnitrile, comprising steps of

(a) forming a first resist layer on a wafer for planarizing the wafer surface;
(b) forming a second resist layer on said first resist layer, the second resist layer consisting essentially of,
a photoactive resin having phenolic hydroxyl groups selected from the group consisting of an admixture of a naphthoquinone diazido sulfonic acid derivative compound and a phenol formaldehyde, and an ester of the reaction of a naphthoquinone diazido sulfonic acid derivative compound and a phenol formaldehyde, and
5 to 50% by weight of trimethylsilylnitrile based on the solid content of the positive resist material,
wherein said first resist layer has a higher plasma etch rate than said second resist layer;
(c) selectively exposing on said second resist layer to form a pattern in that layer;
(d) removing exposed portions of said second resist layer to form a mask pattern in exposed portions of said second resist layer;
and
(e) subjecting said mask pattern and said first resist layer to a reactive ion etching to remove the first resist layer by using the mask pattern as an etching mask.

6 more elements

Dependencies are inferred from the claim text.