Micromachined pixel arrays integrated with CMOS for infrared applications

Large arrays of small micromachined structures with low thermal mass and low thermal-conductance above silicon CMOS substrates and operate as (1) sensitive uncooled IR cameras or (2) high-temperature IR projectors. Arrays of small thin micromachined structures with high thermal masses, are suspended above the underlying silicon substrate by supports that are extremely well thermally isolated from the substrate with a high thermal conductance. This high thermal isolation allows for efficient heating of the microstructure with small currents (the case for microemitters), or small amounts of infrared (IR) incident flux (for microbolometers). The low mass ensures that despite the low conductance, the thermal time constants are in the millisecond range. We show the basic microstructure design common to both microbolometers and microemitters.