A 160 x 120 pixel uncooled TEC-less infrared radiation focal plane array on a standard ceramic package

Abstract

We have developed a 32 μm pitch and 160 × 120 pixel uncooled infrared radiation focal plane array (IRFPA) on SOI by 0.35 μm CMOS technology and bulk-micromachining. For IR detection, we use silicon single crystal series p-n junctions which can realize high uniformity of temperature coefficient and low voltage drift. We have also developed a low-noise CMOS readout circuit on the same SOI which can calibrate the substrate temperature variation in every frame period, comparing two types of pixels, a bulk-micromachined infrared detection pixel and a non-micromachined reference pixel. Then the FPA requires no thermo-electric cooler (TEC) and is mounted on a low-cost standard ceramic package for the consumer products market.

Low-Cost Microbolometer Type Infrared Detectors

“…The design of the ROC significantly affects the power dissipation and the quality of the analog output signal before converting. The most commonly used ROC configuration in microbolometer IRFPAs are direct injection (DI) [ 61 , 84 , 85 ], gate modulation input (GMI) [ 13 , 34 , 35 ], and capacitive transimpedance amplifier (CTIA) [ 20 , 31 , 65 , 86 , 87 ]. The design concepts involve the performance and the structural complexity; each designer may prefer a different design depending on the technical requirement and the process schedule.…”

“… 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.…”

Uncooled Infrared Radiation Focal Plane Array with Low Noise Pixel Driving Circuit

“…Usually, both the IR absorbing structure and thermoelectric converter in a pixel are thermally isolated from the substrate by surface-micromachining or bulk-micromachining techniques. Such thermally isolated pixel structure is essential for converting small IR irradiation to a sufficiently large pixel temperature rise [3].…”