DRY ETCHING METHOD AND APPARATUS THEREOF, PHOTOMASK AND FABRICATION METHOD THEREOF, SEMICONDUCTOR CIRCUIT AND FABRICATION METHOD THEREOF

摘要

PURPOSE: The dry etching method enables the production of a photomask having high accuracy by reducing the dimension difference due to the coexistence of a pattern with high density and low density inside the surface. CONSTITUTION: The dry etching method comprises the steps of etching a Cr metal thin film. The method uses (a) a reactive ion etching gas comprising an oxygen-containing gas and a halogen-containing gas and (b) a reductive gas added in the gas component(a) as an etching gas. The dry etching method enables the fabrication of a photomask by forming a pattern to be transcribed on a wafer on a photomask blank. The fabrication method of photomask is performed by performing a series of pattern formation steps comprising the steps of: forming a resist layer on the photomask blank; exposing and patterning the resist layer; etching the photomask blank; and removing the resist layer.