NSF Award
9903630
This Small Business Technology Transfer (STTR) Phase I project combines a number of key innovations to develop a refractory, highly stable, and ultra-high sensitivity SiC-GaAlN MEMS sensor platform suitable for operating in harsh (high temperature, high pressure, corrosive, and high energy-radiation) environments. This harsh-environment sensor platform is enabled, for the first time, by the integration of three recent innovations: (1) bulk micromachining of single crystal SiC, (2) growth of nitride semiconductor Quantum Well Structures (QWS), and (3) the giant piezoresistance (GPR) effect. GaN-GaAlN QWS devices will be fabricated onto micromachined device-quality single crystal SiC substrates using patented SiC micromachining technologies. SiC is an ideal substrate for growth of nitride semiconductors, and both SiC and GaN-AIN compounds have high (3.0-6.2 eV) band gaps, high melting temperatures (1700-3000 degree C), and excellent mechanical and chemical properties making them eminently suitable for use in harsh environments. The versatility of the giant piezoresistance transduction, SIC-GaAIN sensor platform will first be demonstrated by fabrication of highly sensitive temperature and pressure sensors. <br/> Commercial applications will be in: (a) advanced aeropropulsion control systems; (b) automotive and utilities combustion control systems; and (c ) chemical processing facilities. The proposed harsh environment sensor platform has commercial applications for monitoring of pressure, temperature, flow, acceleration, and sound in advanced aeropropulsion control systems (e.g. turbine engines), automotive and utilities combustion control systems, and chemical processing facilities.
