A DRIE compensation mask pattern for fabricating an extremely thick comb electrode

This paper reports a novel DRIE compensation mask pattern for fabricating an extremely thick sense-comb structure. When we attempted to fabricate a 300-μm-thick sense-comb structure to improve the sensitivity of a capacitive sensor, we found that a bridge-shaped silicon residue (bridge) prevented its formation. We first investigated the detailed property and where the bridge appeared by the DRIE. Based on these investigations, we propose a DRIE compensation pattern to remove the bridge. We successfully formed a 300-μm-thick sense-comb structure by adding the compensation pattern to a tip of the comb structure. Experimental results demonstrated the effectiveness of the proposed compensation pattern.