THREE-DIMENSIONAL PHOTOMASK AND METHOD FOR FORMING THE SAME

摘要

PURPOSE: Provided is a three-dimensional lithographic attenuated phase shift type photomask such that a semiconductor wafer coated with a photoresist can be exposed to light in three different levels of intensity at a time in a photolithographic process. CONSTITUTION: The improved photomask comprises a transparent plate(20) having a layer(21) of a phase shift material(PSM) patterned based on a first configuration and a chromium layer(22) patterned based on a second configuration formed on the patterned PSM layer. The first and second configuration correspond to the respective different masking levels. By using the photomask, a photoresist layer(24) having a wavy surface can be produced by exposing a semiconductor wafer once in the photolithographic process.