SOI-CMOS Platform for Monolithically Integrating High-Voltage Driver Circuits with Bulk-Micromachined Actuators

We present a newly developed technology platform for monolithically integrating high voltage DMOS (double-diffused metal oxide semiconductor) circuits upwards of 40 V with bulk-micromachined actuators (XY-stage) using both the top and the bottom surfaces of an SOI (silicon-on-insulator) wafer. Driver circuits were pre-fabricated on an 8-mum-thick SOI wafer by the DMOS processes, after which MEMS electrostatic actuators were integrated into the identical SOI layer as well as the substrate by post-processing using DRIE (deep reactive ion etching). Thanks to this monolithic integration technique, multi-layered high-aspect-ratio structures were produced.