Clean Technology 2007
D. Starikov, C. Boney, R. Pillai and A. Bensaoula
Integrated Micro Sensors, Inc., US
ultraviolet, infrared, photodetector, single chip, solar-blind, fire detector
Currently used flame detectors that are composed of discrete UV and IR solid-state components are bulky, sustain temperatures only below 125°C, and are not capable of detecting a multi-band optical signal with high spatial resolution. Most current solid-state IR sensing devices require intensive one or even two-stage cooling. <br>Group III-nitride semiconductor materials are superior for advanced multi-band optical sensor fabrication due to their wide direct band gap and high thermal, chemical, mechanical, and radiation tolerance. <br>Miniature, inexpensive chip-based dual-color high-temperature and radiation-resistant solar-blind optical sensor would allow early false alarm-free fire detection through distributed sensors, placed closer to potential flame sources, and provide a fast and reliable response in separated UV and IR bands with high spatial and time resolution. <br>Demonstration of packaged UV/IR photodetectors based on a single-chip integration of III nitride materials on commercial Si and sapphire wafers will be presented. The UV-sensitive photodetector structure is based on Schottky or p-i-n diodes fabricated on AlGaN layers with high Al content grown by RF MBE. The IR-sensitive part of the photodetector is based on Si or silicide Schottky diodes fabricated on the same Si or SOS substrate, with Si also serving as a filter for the visible wavelength range.