Process Optimization and Performance Improvement of CMOS Microbolometer With A Salicided Polysilicon Thermistor

In this study, the absorptivity of a polysilicon microbolometer based on standard CMOS technology at a wavelength of 7-13 μm is improved by the deposition of silicon nitride (Si 3 N 4 ). The influence of process temperature and thickness on absorptivity of microbolometer are investigated. Simulation results show that the absorptivity of the microbolometer increases significantly with the increased thickness of Si 3 N 4 in the wavelength range of 8-10 μm and 10.5-13 μm. The experimental results demonstrate that the average detectivity of the microbolometer in the range of 10-13 μm can be further improved by 87.10% when the deposition temperature of Si 3 N 4 film is increased to 300 °C. When the thickness of the Si 3 N 4 film is increased to 300 nm, the average detectivity of the microbolometer in the range of 10-13 μm can be improved by 152.55%.