METHOD OF IMPROVING UNIFORMITY OF CRITICAL DIMENSION WITHIN SURFACE AREA

摘要

PROBLEM TO BE SOLVED: To enhance the yield of a semiconductor device by solving the bias problem of a critical dimension difference between the center and edge of a wafer. SOLUTION: Uniformity of critical dimensions within a surface area is improved by using double exposure and double etching. A coating layer is formed on a wafer composed of a first area and a second area. The first area and the second area are patterned with different processes. CD (critical dimension) uniformity between the central part and the edge part of the wafer using the two different processes improves a known single-stage patterning process, and the yield is enhanced.