Scale down of p-n junction diodes of an uncooled IR-FPA for improvement of the sensitivity and thermal time response by 0.13-µm CMOS technology

Low-Cost Microbolometer Type Infrared Detectors

“… Trends of the pixel size reduction for complementary metal oxide semiconductor (CMOS)-compatible microbolometer infrared (IR) detectors, data taken from (in left-to-right order) [ 12 , 13 , 14 , 15 , 17 , 18 , 19 , 20 , 21 , 22 , 25 , 27 , 28 , 29 , 31 , 32 , 33 , 34 , 35 , 37 , 39 , 40 , 41 , 43 , 46 ]. …”

“…The reason is that the thermal IR detectors are considered to be much slower and less insensitive than the photon IR detectors [ 6 ]. In 1992, both Texas Instruments and Honeywell published their uncooled IRFPAs (infrared focal plane array) based on pyroelectric type and microbolometer type thermal detector, respectively, with fascinating performance [ 10 , 11 ], successfully encouraging a sustained effort to further reduce the pixel size, improve the device performance, and reduce the production cost [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 ].…”

“…Not only does the high-integration process lower the production cost of the detectors, but also it provides mature approach with small feature size and high uniformity to benefit the pixel size and the device performance. Especially, the complementary metal oxide semiconductor (CMOS) microbolometer technology is developed for long-wavelength IR (LWIR, 8–14 μm) FPAs via CMOS foundry compatible approaches [ 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 ]. During the fabrication process, the layer structures of the absorber and the thermal sensor are formed with CMOS process, and then post-CMOS micro-electro-mechanical system (MEMS) process are used to form suspended microbridge structures in purpose of thermal isolation.…”