Porous Silicon: From Formation to Applications: Optoelectronics, Microelectronics, and Energy Technology Applications, Volume Three

Chapter 6

Surface Micromachining (Sacrificial Layer) and Its Applications in Electronic Devices

Alexey Ivanov and Ulrich Mescheder

6.1 Introduction

Sacrificial layers are used in microelectronics and microsystems technology to form freestanding functional elements, which are isolated thermally, electrically, or mechanically from substrate. Surface micromachining (SMM) is an approach to fabricate microelectromechanical systems (MEMS). SMM is compatible with CMOS technology, and thus allows the monolithic integration of microelectronics and MEMS. In SMM, typically silicon oxide, photoresist, or aluminum are used as a sacrificial layer to form void space between substrate and freestanding functional structures on top of it (Mescheder 2004; Korvink ...