METHOD OF MANUFACTURING PHASE SHIFT MASK

摘要

PROBLEM TO BE SOLVED: To decrease the production time and cost by selectively etching a second region of a light-shielding material layer by using a second photoresist pattern as an etching barrier, and by eliminating the second photoresist pattern. SOLUTION: Electron beams are radiated in such a manner that the energy to irradiate a phase inversion projecting area is relatively higher than in a normal projecting area. The photoresist in the phase inversion projecting area is completely developed to expose a chromium layer. In this process, the developing rate in the normal projecting area is relatively slower. Then the photoresist pattern 5A is used as an etching mask to selectively etch the exposed chromium layer to form trenches in a part of a transparent substrate. Further the resist is developed and removed in the normal projecting area to form another photoresist pattern 5B. This photoresist pattern 5B is used as an etching mask to remove the exposed chromium layer. In the final process, the photoresist pattern 5B is removed.