Development of UV-NIL resist for semiconductor device manufacturing

A resist design for UV-NIL process was investigated, aiming to improve throughput and defects in semiconductor device manufacturing. To improve throughput, a novel low volatility and low viscosity resist was developed to enable ink-jetting with minute resist droplets. Direct observation of resist spreading showed that the resist filling process is composed of three steps: capillary bridge formation, resist spreading, and bubble dissolution. The resist filling time can be decreased by increasing the wettability of the resist to the mold material and reducing the viscosity of the resist. Bubble dissolution is the dominant factor in throughput, and minimizing trapped bubble volume is the most effective approach. To decrease the release defects, resists with various acrylate monomer structures and formulations were studied in the terms of elastic modulus of UV cured resist films. It was found that there is a good correlation between modulus of the resist and release force.