Exposure latitude of deep-ultraviolet conformable contact photolithography

Abstract

The authors present for the first time a study of the exposure latitude of deep-ultraviolet conformable contact photolithography in a nonevanescent regime. Exposures of grating patterns with half-pitches ranging from several hundred nanometers to 100nm are simulated and experimentally demonstrated using an optimized trilayer resist stack. They show that a mask geometry with the absorber embedded in the glass improves image contrast, and therefore exposure latitude over a conventional chrome-on-glass mask geometry. They show that conformable contact photolithography is suitable for printing 500–100nm half-pitch features with an exposure latitude of ±22% for ±15% linewidth tolerance.