IR-SENSOR ARRAY FABRICATION IN PB1-XSNXSE-ON-SI HETEROSTRUCTURES

Large line or area arrays of photovoltaic infrared sensors are desired for thermal imaging and spectroscopic applications. The sensor arrays should be arranged on Si-substrates because of size, costs and the po ssibility to integrate the read-out electronics of large arrays direct ly into the Si-substrate. We therefore grow narrow gap Pb1-xSnxSe laye rs by molecular beam epitaxy (MBE) on Si(111)-substrates. A CaF2 epita xial buffer layer is used for compatibility reasons. Photovoltaic infr ared sensor arrays for the 8-12 mu m atmospheric window are fabricated in the 2-4 mu m thick layers by photolithographic techniques with 8 m ask levels and 6 simple wet etching steps. The operability of the sens or arrays is demonstrated by recording thermal images with a simple ca mera.