JPS6442133A - Taper etching of insulating film - Google Patents

Abstract

PURPOSE:To execute a two-stepped shape taper etching operation in a single process by a method wherein a resist mask is heat-treated, a cross-sectional shape of a sidewall is formed like an overhang where an angle of the sidewall with reference to the surface of an insulating film is larger than 90 deg. and the insulating film is etched while a sidewall protective film is being formed. CONSTITUTION:If a pattern of a resist 3 formed on an insulating film 2 is heat-treated, the resist 3 is melted and an overhang shape whose angle at sidewalls with reference to the surface of the insulating film is larger than 90 deg.. Then, if an etching operation is executed by using a reactive ion etching device by making use of the resist as a mask under a condition of low selectiv ity, the etching operation of the insulating film proceeds anisotropically in an initial period. if an overhang part of the resist 3 is removed, a taper-shaped etching operation gradually proceeds. During this process, a deepest part for the etching operation is etched nearly anisotropically in accordance with the perpendicular sidewalls; a two-stepped shape taper etching operation is executed. By this setup, the taper etching operation whose process is simplified can be executed; a cost can be reduced.