Imprint template fabrication based on glass wet etching using a soft etching mask

Abstract

This paper presents a simple and reliable imprint template fabrication process for MEMS based on glass wet etching using a single-layer photoresist as the etching mask. In this work a novel vapour deposition process is adopted to cover a thin layer of silane coupler on the glass surface to improve the adhesion strength of the resist and hence attenuate the undercutting phenomenon, which reduces the extra undercut ratio to 0.6 and improves the sharpness of the etched pattern edges. Since the air bubbles in the photoresist and the particle contamination on the glass surface will cause some defects on the etched surface, the authors adopted a thick layer of resist to eliminate defects and reduce the stringent requirement for clean-room conditions. A smooth template surface is obtained by using hydrochloric acid as an etching agent additive, which can facilitate the template separation in the imprint lithography process. Imprint templates with a pattern feature size of 100 µm have been fabricated using the developed process and the imprint results are demonstrated.