Development of sacrificial layer wet etch process of TiNi for nano-electro-mechanical device application

Abstract

We report the wet etching of titanium nickel (TiNi) films for the production of nano-electromechanical (NEM) device. SiO2 and Si3N4 have been selected as sacrificial layers of TiNi metal and etched with polyethylene glycol and hydrofluoric acid (HF) mixed solution. Volume percentage of HF are varied from 10% to 35% and the etch rate of the SiO2, Si3N4 and TiNi are reported here. Within the various experiment results, 15% HF mixed polyethylene glycol solution show highest etch ratio between sacrificial layer and TiNi metal. Especially Si3N4 films shows high etch ratio with TiNi films. Wet etching results are measured with SEM inspection. Therefore, this experiment provides a novel method for TiNi in the nano-electro-mechanical device.