High performance infra-red detectors based on Si/SiGe multilayers quantum structure

Recently, single crystalline (Sc) Si/SiGe multi quantum structure has been recognized as a new low-cost thermistor material for IR detection. Higher signal-to-noise (SNR) ratio and temperature coefficient of resistance (TCR) than existing thermistor materials have converted it to a candidate for infrared (IR) detection in night vision applications. In this study, the effects of Ge content, C doping and the Ni silicidation of the contacts on the performance of SiGe/Si thermistor material have been investigated. Finally, an uncooled thermistor material with TCR of −4.5%/K for 100 μm × 100 μm pixel sizes and low noise constant (K1/f) value of 4.4 × 10−15 is presented. The outstanding performance of the devices is due to Ni silicide contacts, smooth interfaces, and high quality multi quantum wells (MQWs) containing high Ge content.