"Schottky-Barrier Infrared Charge-Coupled Device Focal Plane Arrays"

Recent development of high-performance Pd2Si and PtSi Schottky-barrier IR-CCD image sensors make these monolithic focal plane arrays attractive for many SWIR and thermal imaging applications. PtSi Schottky-barrier detectors operated at 80K have quantum efficiency of several percent in the 3 to 5 μm spectral range and cut-off wavelength of about 6.0 μm. Pd2Si Schottky-barrier detectors operated between 120 and 140K have cut-off wavelength of 3.6 μm and quantum efficiency in the range of 1.0 to 8.0% in the SWIR band. High-quality thermal imaging was achieved with a 64x128-element PtSi Schottky-barrier IR-CCD imager in a TV compatible IR camera operated with 60 frames per second. This paper reviews the Schottky-barrier IR-CCD technology developed at RCA. A model for photoyield of Schottky-barrier detectors (SBDs) is reviewed and compared with experimen-tal data. The architecture and design trade-offs of the SBD IR-CCD imagers are discussed. Also included is a discussion of the quantum efficiency requirements for staring thermal imagers and the performance achievable with the Schottky-barrier IR-CCD arrays.