PHASE SHIFT MASK AND ITS PRODUCTION

摘要

PURPOSE: To surely shield the peripheral part of an effective region of a halftone phase shift mask from light by a simple method without using a complicated light-shielding band which is conventionally used. CONSTITUTION: A translucent phase shift film 2a of a desired pattern and a light-shielding film 11b of almost the same pattern are formed on a transparent substrate 1 by etching. Substrate 1 consists of the effective region 8 of an area (a×b) where the desired pattern is formed and the peripheral part 9 surrounding the effective region. The light-shielding film 11b is deposited on both of the phase shift film 2a in the peripheral part 9 and the phase shift film 2a in the effective region 8. However, the edge of the phase shift film 2a is formed to project in the horizontal direction by length Z from the edge of the light- shielding film 11b. With this projected part, the phase of exposure light is inverted between the light-shielding part and the light-transmitting part which interpose the projected part between them so that these parts can be clearly separated from each other.