Imprint template fabrication method for MEMS based on wet etching

A fast and low-cost imprint template fabrication process is presented, which is based on glass wet etching using a soft etching mask. The emphasis is focused on the improvement of the pattern geometry profile and the surface quality. After analyzing the undercut formation mechanism, silane coupler coating process is optimized by investigating the effects of various coating methods, evaporation time and temperature of silane coupler on the etched results, which reduces the undercut ratio to 0.6 and improves the pattern profile. The main contributors to the surface roughness are identified by comparing the solubility product constant of various insolubles produced during etching, and good surface quality is obtained by using hydrochloric acid as etching additive. Main factors causing surface defects are analyzed and thick soft etching mask is adopted to eliminate the surface defects. The imprint template with pattern feature size of 100 μm is fabricated using the developed process. The preliminary imprint experiments are performed and high fidelity replicas of the pattern on template are obtained.