PRODUCTION OF HALFTONE PHASE SHIFT PHOTOMASK

摘要

PURPOSE:To obtain the process for production of the halftone phase shift mask with a decreased number of stages. CONSTITUTION:This process for production of the halftone phase shift photomask formed by laminating halftone light shielding patterns 15 and phase shifter patterns 16 in this order on a transparent substrate 14 includes a stage for forming a silicon layer 15 on the transparent substrate 14, a stage for forming a silicon oxide layer 16 by subjecting the surface of the formed silicon layer 15 to an oxidation reaction treatment, a stage for forming the phase shifter patterns 16 by etching away 19 the prescribed parts of the silicon oxide layer 16 and a stage for forming the halftone light shielding patterns 15 by etching away 20 the prescribed parts of the unoxided silicon layer 15.