Chemical trimming overcoat: an advanced spin-on process for photoresist enhancement in EUV lithography

The semiconductor industry is on the rise of maturing EUV lithography in high volume manufacturing (HVM). There remain, however, challenges to be overcome in the advancement of photoresist to improve yield and reduce cost of ownership. Herein, we report a novel chemical trimming overcoat process as a post-lithography spin-on solution to enhance EUV photoresist performance, enabling effective photospeed reduction as well as process window enhancement, such as reducing bridging defect at underdose. This is a highly versatile and tunable process for most chemically amplified photoresists, therefore allowing it to become a general process for a wide range of applications across EUV lithography.