Alumina Porous Membranes Obtained by One-Step Anodizing Process in H2SO4 for MEMS Packaging

Abstract

A MEMS packaging technique based on porous alumina films is proposed. This method allows for low temperature, wafer level packaging of the devices. We report on initial experiments indicating the feasibility of the technique. Patterned porous alumina films are created by anodizing aluminum films on wafer substrates using shulphuric acid electrolytes. Etching of the barrier layer through the porous membrane by plasma with CF 4 +O 2 gas and evidence of pore opening required for the release of a sacrificial MEMS layer are presented.