Effect of porous silicon formation on stiction in surface micromachined MEMS structures

Abstract

Stiction, or adhesion of components to one another, is a major failure mechanism in surface micromachined MEMS. In this paper we discuss roughening of the surface of polysilicon, which forms the structural layer in surface micromachining, by the formation of porous silicon and its effect on stiction. The adhesivity of the surface is investigated by measurements of contact angle and the roughness is measured by a surface profiler. Measurements to estimate stiction on surface micromachined cantilevers and accelerometers are reported. © 2005 WELEY-VCH Verlag GmbH & Co. KGaA, Weinheim.