Fabrication and performance of a novel CMOS infrared emitter

Si-based thermal infrared emitter is one of the key components of the micro NDIR gas sensor. In this paper, a low power, low-cost, and radiation enhanced thermal infrared emitter was developed and fabricated based on a commercial standard CMOS technology. A CuO-MnO2 film with porous structures was deposited on the center of the freestanding membrane of the device by electrohydrodynamic inkjet printing to enhance the infrared emission. The CMOS infrared emitter takes only about 150 mW to reach 500 ℃. The modulation depth is larger than 90% at 10 Hz and about 50% at 50 Hz. Both the emission spectrums and the infrared radiation power results confirmed that the printed radiation enhance layer significantly improved the radiation intensity of the device in a mid-infrared wavelength of 2.5-8 μm. The stability of the devices was tested by studying the resistance drifts of the emitters after operation for a period of time. The emitter shows excellent stability at 450 ℃ and below. The resistance drift of the emitter operating at 500 ℃ was reduced to about half of the unannealed devices by electrothermal annealing at 650 ℃ for 10 min. The CMOS infrared emitter can be easily integrated with CMOS interface circuits in the future to achieve highly integrated smart sensor.