Post-CMOS Integration of MEMS Inertial Sensors Using Oxidized Porous Silicon Technique

Abstract

In this work, a low-cost and CMOS-compatible fabrication method to produce CMOS-MEMS porous silicon inetial sensors by using a thick oxidized prous silicon (OPS) layer is demonstrated. The OPS layer was fabricated before the standand CMOS process used for defining the contour of MEMS structures as well as dielectric isolation. This OPS techique has a substantial cost advantage over DRIE techniqe and can porduce very thick layers without severe stress problems. Two kinds of MEMS inertial structures have been produced and the residual stresses of the OPS substrate were measured.