The development and optimization of the photoresist module qualification procedure

A new technique for qualifying and monitoring the photoresist module was optimized. Test wafers with an etched SRAM pattern were inspected before and after photoresist processing. Inspections were performed using an OSI IQ-165 patterned wafer inspection system that employs optical pattern filtering. This system is capable of increasing sensitivity without increasing inspection time. Defect source analysis (KLA 2551) was used to identify and map the defects added by the photoresist module. This technique was compared to the traditional photoresist qualification procedure that evaluates resist patterned on bare silicon wafers.