Plasma Etching of Tapered Features in Silicon for MEMS and Wafer Level Packaging Applications

This paper is a brief report of plasma etching as applied to pattern transfer in silicon. It will focus more on concept overview and strategies for etching of tapered features of interest for MEMS and Wafer Level Packaging (WLP). The basis of plasma etching, the dry etching technique, is explained [1] and plasma configurations are described elsewhere [2][3]. An important feature of plasma etching is the possibility to achieve etch anisotropy. The plasma etch process is extremely sensitive to many variables such as mask material, mask openings and more important the plasma parameters.