INFRARED THERMOPILE SENSOR-BASED ON ALGAAS-GAAS MICROMACHINING

Infrared bolometry is demonstrated using broadband gold black absorbers positioned on micromachined AlGaAs membranes of high thermal resistance. With a cascade of 20 AlGaAs thermocouple, the radiation-induced temperature difference is measured. Black-body radiation in the range of 315-530 K is used to test the sensor and a sensitivity of R = 145 V W-1 and corresponding detectivity of D*=4.1x10(7) cm Hz(1/2) W-1 are reached. The relatively simple technology that is compatible with MESFET technology results in thermopile sensors that are compared to similar sensors fabricated in polysilicon and Bi-Sb-Te technologies.