PB1-XSNXSE-ON-SI LWIR SENSOR ARRAYS AND THERMAL IMAGING WITH JFET CMOS READ-OUT/

Long wavelength infrared (LWIR) sensor arrays were fabricated in Pb-1- x SnxSe layers grown epitaxially on Si-substrates by MBE. A CaF2 inter mediate buffer layer approximate to 30 Angstrom thick was employed for compatibility reasons. The photovoltaic sensors are based on the bloc king Pb-contact technique on p-type material. They were fabricated usi ng simple wet-etching process steps only. Cut-off wavelengths were abo ut 10.5 mu m, quantum efficiencies >60%, and resistance-aera products above 3 Omega 2-cm(2) at 90K. A demonstrational LWIR thermal imaging c amera was assembled with a 256 element line array with 50 mu m pitch. Low-noise signal processing was achieved with sensors with differentia l resistances in the 10 kOhm range by using JFET/CMOS technology. For each channel, an integrator, correlated multiple sampling and sample/h old amplifier was used before multiplexing to a common output.