Near edge x-ray absorption fine structure measurements of surface segregation in 157 nm photoresist blends

The use of near edge x-ray absorption fine structure spectroscopy (NEXAFS) for studying the surface chemistry of photoresist blends at the 157 nm mode was analyzed. The objective of the study was to quantify component segregation and identify surface phenomena, which affected pattern formation. It was observed that the protected copolymer caused wetting of the surface of the blend film. The deprotected version of the copolymer was found with a lower water contact angle than the homopolymer. The surface segregation was witnessed during normal photoresist processing, specifically during the spin coating and baking steps.