FABRICATION OF SEMICONDUCTING YBACUO SURFACE-MICROMACHINED BOLOMETER ARRAYS

Thermal infrared detectors require thermal isolation to permit the inf rared-sensitive material to integrate the incident photon energy and t hereby obtain high responsivity and detectivity, This paper describes the fabrication of semiconducting YBaCuO microbolometer arrays into th ermal isolation structures by employing Si surface-micromachining tech niques. An isotropic HF:HNO3 etch was used to remove the underlying Si substrate from the front-side of the wafer and suspend SiO2 membranes into 1 x 10 pixel-array structures, The infrared-sensitive material, YBaCuO, was subsequently deposited onto the thermal isolation structur es and patterned to form the detector arrays, The high-temperature coe fficient of resistance and low noise of semiconducting YBaCuO at room temperature is attractive for uncooled infrared detection, The fabrica tion process was conducted entirely at room temperature, In this manne r, infrared detectors are fabricated in a process that is compatible w ith CMOS technology to allow for the integration with on-chip signal p rocessing circuitry, The end result is low-cost infrared-detector arra ys for night vision in a variety of applications including transportat ion and security, Preliminary results show a temperature coefficient o f resistance above 3%, voltage responsivity close to 10(4) V/W, and de tectivity over 10(7) cm.Hz(1/2)/W bias current of 0.79 mu A.