A 512×512-element PtSi Schottky-barrier infrared image sensor

An infrared image sensor with video quality has been developed for thermal imaging in the 3-5-μm infrared band. The array size is 512×512. The device uses a platinum silicide (PtSi) Schottky-barrier photodetector. The charge sweep device architecture is applied to obtain a large fill factor. The pixel has a two-level polysilicon and two-level aluminum structure with a minimum design rule of 2 μm. The pixel size and fill factor area 26×20 μm/SUP 2/ and 39%, respectively. The responsivity has been improved by use of a thin metal film and an optical cavity structure. The barrier height is 0.22 eV, which corresponds to the cutoff wavelength of 5.6 μm. The device operates at the standard TV frame rate. The noise at 300 K with f/1.5 optics is limited by the shot noise of the detector, and the device has the capability of resolving a 0.11 K temperature difference. High-quality infrared imagery has been obtained with a prototype infrared TV camera using this device.