ZnO Etching and Microtunnel Fabrication for High-Reliability MEMS Acoustic Se…

This paper describes a technique for uniform step coverage of aluminum metal (Al) on ZnO film in the fabrication of MEMS acoustic sensor. The MEMS acoustic sensors were fabricated by etching ZnO layer in three different etchants: HCl, NH4Cl with electrolytically added copper ions, and NH4OH with electrolytically added copper ions. For the first time, a technique is reported, which uses aqueous …