Evaluation and Analysis of Physical Properties of Nanomaterials for Highly Sensitive Mechanical Sensing Devices

Abstract

This technical note is a review of the contract research at Ritsumeikan University for the “Highly Integrated, Complex MEMS Production Technology Development” Project (“Fine MEMS” Project) sponsored by New Energy and Industrial Technology Development Organization (NEDO). Our research focuses on characterization of physical properties of nanoscale microelectronic materials and carbon nanotube (CNT) to elucidate new effects for potential applications in advanced micro/nano electromechanical devices, and consists of two main parts. The first part deals with experimental evaluation of mechanical, thermal, and electrical properties of tungsten silicide (WSi) and CNT thin films. We have clarified that the WSi film will be promising as a structural material for high-performance capacitive micro accelerometer. In the second part, piezoresistive effect of single crystal silicon nanostructures has been theoretically and experimentally investigated. The p-type ultra-thin silicon nanowire (SiNW), in particular <001> oriented SiNW, will be a good piezoresistor with a giant longitudinal piezoresistance coefficient. We have carried out the research in cooperation with Hitachi, Ltd. and National Institute of Advanced Industrial Science and Technology (AIST), and these cooperative relationships have greatly contributed to the advancement of the research and development. Achievements in the contract research are very promising and significant for mechanical sensing applications.