Infrared vidicons employing metal-silicon Schottky diode arrays

Metal-silicon Schottky barrier diode arrays have been suggested for use as retinas in infrared ridicons (1). Such arrays permit the fabrication of camera tubes having highly uniform retina response out to the mid infrared, thus permitting sensitive storage mode imagery even in the presence of substantial background radiation (2). To achieve the required long wavelength cutoff, high work function metals (e. g., Pd, Pt) or their silicides must be used on P-type silicon. This results in a diode polarity opposite to that normally used in low beam velocity silicon diode vidicons, and requires the use of a high velocity electron beam scan to bias the diodes properly. This paper describes the experimental apparatus used to show the feasibility of this novel approach to infrared imagery, the interactions observed between a fast (∼ 250 volt) electron beam and the silicon diode mosaic, and the characteristics of the imagery observed to date.