Projection exposure method and an optical mask for use in projection exposure

摘要

A projection exposure method includes the steps of (a) irradiating a light from a light source on an optical mask, where the optical mask includes a main space which transmits light and has a desired exposure pattern, and a subspace which transmits light and is provided adjacent to the main space, and (b) exposing a photoresist layer by the light which is transmitted through the optical mask via a lens so as to project an optical image of the main space, where the subspace has a narrow width such that the light transmitted through the subspace by itself does not expose the photosensitive layer.