Investigation on micromachining technology compatibility of PECVD SiO 2/Si3N4 double-layer electrets

In this paper PECVD SiO2/Si3N4 double-layer electrets were investigated for their compatibility with micromachining technology, such as conventional lithography and etching techniques. After the experiments, we find that no matter under what condition, either high temperature or high humid condition, could H3PO 4 improve the charge stability of SiO2/Si 3N4 double-layer electrets a little. RIE and oxygen plasma stripping reduce the charge stability significantly. Acetone stripping does not influence the charge stability in high temperature and high humidity. The other techniques, such as BHF, fuming nitric acid stripping, corrosive of Al and Au etc., decrease the charge stability a little. ? 2008 IEEE.EI