Patterning high aspect silicon pillars on cantilever by metal assisted chemical etching for humidity sensing

Abstract

Pillars formed by metal assisted chemical etching (MACE) process as a post process on a silicon cantilever are presented in this work. Although the cantilever is very fragile, the patterning of the pillar structures on the cantilever have been successfully demonstrated. The high aspect silicon pillar structures from 20 to 40 with smooth surfaces and vertically etched shapes on the cantilever are formed by MACE. In addition, silicon cantilever with high aspect ratio pillars on its surface is proposed for humidity sensing application. The humidity sensing utilize the principle that the pillars stack together based upon the condensation behavior of water vapor on their surfaces.