PROJECTION EXPOSURE METHOD, THE MASK THEREOF

摘要

A method of projection exposure utilizing a mask including a step of exposing an object by utilizing a transparent mask substrate of which the upper surface is slanted at a predetermined angle from a direction perpendicular to the light path and an opaque film pattern is formed at regular intervals on a lower surface of the mask substrate so that the phase difference between adjacent mask patterns occurs due to the slanted mask substrate, thereby reducing the minimum pitch available for pattern formation without a shorter-wavelength light source and without increasing NA by reducing the frequency difference delta v to the pitch d of the mask in a given wavelength of a light source and NA.