Patent ID: 6428938
Filing Date: 2002-08-06
Classification: G03F

Abstract:
A method for fabricating phase-shift masks comprising the steps of:providing a transparent plate; depositing an optically opaque blanket layer on said transparent plate; depositing a photoresist layer on said opaque layer; partially exposing said photoresist layer to form images in regions A while fully exposing said photoresist in alternating regions B; developing said photoresist to completely remove said photoresist in said regions B thereby exposing said opaque layer while retaining portions of said photoresist in said regions A; etching said opaque layer in said regions B to said transparent plate; plasma etching said photoresist and removing said portions of said photoresist in said regions A; plasma etching to recess said transparent plate in said regions B to form a phase-shift mask; etching selectively said opaque layer in said regions A and removing said photoresist to complete said phase-shift mask.