A 512 X 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- mu m infrared band. The array size is 512 multiplied by 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 mu m. The pixel size and fill factor area 26 multiplied by 20 mu m**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 mu m. 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.