Patent ID: 6020109
Filing Date: 2000-02-01
Classification: G03F

Abstract:
A semiconductor integrated circuit device fabrication method, comprising the steps of: (1) irradiating an at least partially coherent exposure light beam onto an integrated circuit pattern over a phase shifting mask, and (2) transferring the integrated circuit pattern onto a photoresist film over a wafer by reduction-projecting the integrated circuit pattern onto the photoresist film over the wafer, said phase shifting mask comprising:(a) a light shielding region, a first light transmission region, and a second transmission region which is isolated from the first light transmission region by the light shielding region, which light shielding region, first light transmission region, and second transmission region constitute the integrated circuit pattern and are formed on a mask pattern plane;(b) a transparent mask substrate having a first major surface, which first major surface is opposed to and in contact with the mask pattern plane; and(c) a recess region in the first major surface of the transparent mask substrate, which recess region is formed at a position opposite the second transmission region,wherein the recess resin covers the second transmission region and is formed over a periphery thereof and into a part of the light shielding region adjacent to the second transmission region, and the depth of the recess region is such that a phase of the transmitted exposure light beam through the second transmission region is inverted as compared with that of the transmitted exposure light beam through the first light transmission region so that the transmitted light beams through the first light transmission region and the second transmission region will interfere with each other.