Single crystal silicon MEMS fabrication based on smart-cut technique

• Published in: Sensors and actuators. A. Physical. 2004-04, Vol.112 (1), p.116-121
• Main Authors: Du, J., Ko, W H, Young, D J
• Format: Article
• Language: English
• ISSN: 0924-4247
• DOI: 10.1016/j.sna.2003.11.027

A new single crystal silicon MicroElectroMechanical Systems (MEMS) fabrication process is proposed using proton-implantation smart-cut technique. Compared to conventional silicon on insulator (SOI) wafer fabrication processes for MEMS applications, this technology can potentially result in a significant substrate and processing cost reduction. A silicon layer with 1.79 micron thickness has been achieved over an oxidized 4-in silicon substrate using the proposed technique. TEM analyses of the silicon thin film reveal single crystal characteristics, which is attractive for potential integration of MEMS devices with microelectronics in the same structural layer. Implant-induced defect density in the silicon can be substantially reduced to a negligible level through high temperature annealing. Prototype single crystal silicon MEMS structures, such as cantilever beams and clamped-clamped micro-bridges with a typical length of a few hundreds of micrometers, have been successfully fabricated as demonstration vehicles for future micro-systems implementation.