Fabrication of surface micromachined polysilicon actuators using dry release process of HF gas-phase etching

Abstract

The HF GPE (gas-phase etching) process was newly developed for the dry-release of sacrificial oxide in polysilicon surface micromachining. Using anhydrous HF gas and CH/sub 3/OH vapor, we successfully fabricated vibrating micro-gyroscope structures with virtually no process-induced stiction. Compared with conventional wet-release, HF GPE process showed more than eight times longer detachment length, which enables highly sensitive sensors.