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Prototypes of VO2-based bolometric detectors with lateral dimensions of 25 X 25, 30 X 30, 35 X 35, 40 X 40 and finally 50 X 50 micrometers2 and fill factors approaching 90% are presented. These detectors are grouped in hardwired linear arrays as large as 512 X 1 pixels. Under DC biasing, the fabricated detectors, even the smallest ones, exhibit responsivities from 48,000 to 120,000 VW-1, detectivities in the range of 1.5 X 108 cm Hz1/2W-1 and response times in the range of 5 ms. These new bolometric detector structures contain hidden-legs placed completely underneath the bolometer platform. Results of simulations of the mechanical, optical and electrical properties of these new detector structures are presented. A complete detector fabrication process flow is described.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

A novel type of light modulating micromirror device has been designed and fabricated. A unique hinge structure provides the device with the potential for modulating both the phase and amplitude of light signals, while its high thermal conductivity makes the device amenable to high power laser applications. An extremely high fill factor can be attained since the hinges lie entirely beneath the mirror surface. This hidden hinge structure is comprised of a single level and therefore involves a simple fabrication process. Micromirrors with dimensions ranging from 100 micrometers X 100 micrometers to 300 micrometers X 300 micrometers with maximum deflection angles from 2 degree(s) to 4 degree(s) were fabricated. The devices were characterized in terms of the reflecting surface optical quality, the operational modes attainable, the critical voltages (as low as 15 volts), and the response time (as short as 125 microsecond(s) ).

Several prototypes of individual VO 2 -based bolometric detectors and their arrays consisting of 64 by 64, 128 by 128 and 240 by 320 pixels are presented. The fabrication method and the device characterization results are described. Three types of readout integrated circuits for the arrays are also presented. A custom vacuum package for the IR bolometric detector arrays is descried.

Uncooled IR bolometric detectors fabricated using surface silicon micromachining are presented. The detector fabrication process employs a polyamide sacrificial layer, and a VO2 thermistor layer exhibiting a thermal coefficient of resistance on the order of -3 percent/degrees C. Detector sizes are 100 micrometers X 100 micrometers and 50 micrometers X 50 micrometers , and 64 X 64 and 128 X 128 pixel arrays are fabricate. The detectors exhibit responsivities of up to 15 000 VW-1, normalized detectivities typically exceeding 108 cm Hz1/2W-1, and response times below 20 ms. Three integrated readout circuit designs for 64 X 64 and 128 X 128 pixel detector arrays, fabricated using a standard 1.5 micrometers CMOS process,a re described. These circuits include several test and detector nonuniformity correction features and can operate in either self scanning mode at a rate of 30 frames per second, or in the random access mode in which column and row addresses are input directly.