Progress in qualifying and quantifying the airborne base sensitivity of modern chemically amplified DUV photoresists

Atmospheric pressure deep UV lithography using fast chemically amplified photoresists will be the mainstay of semiconductor production into the foreseeable future. Airborne base contamination of modern resists is a yield-limiting issue that has lacked quantitative correlation to resist performance. Herein, the authors discuss the affect and implications of molecular base contamination on a state-of-the-art 248nm chemically amplified photoresist. The results of this work suggest that contamination control will become even more critical as we enter the era of low K-1 factor 150nm device production using 248nm lithography. The experimental work that supports these conclusions was performed at IMEC, Leuven, Belgium.