Method for producing multi-level contacts

摘要

The present invention relates to a method for overcming problems of amplified exposure light interference from shrinked devices and difficulties of photolithographic and etching process control due to multi-level contacts. The present invention combines reflective lights from multiple levels into one single light and reduces interference of reflective lights by introducing a reflective coating and an anti-reflective coating of SiON/Ti or SiON/TiN/Ti which further serve as an etching hard mask for avoiding overetching. The process windows are expanded. Semiconductor devices can be further shrunk and production yields an be improved.