Two-dimensional monolithic lead-chalcogenide on active Si-substrate IRFPA

Abstract

Narrow gap IV-VI layers grown epitaxially on Si(111)-substrates by molecular beam epitaxy exhibit high quality despite the large lattice and thermal expansion mismatch. We present the further development of the first realization of a 2-d narrow gap IR-FPA an a Si-substrate containing the active addressing electronics: A 96 × 128 array with 75μm pitch for row-by row electronic scanning and parallel read-out of the line addressed. Each pixel contains a bare Si-area onto which epitaxial growth occurs, and an access transistor. A MWIR PbTe layer is grown by MBE onto completed Si-read-out substrates at temperatures below 450°C. Photovoltaic sensors are then delineated in the layers. Each pixel is connected to the Si read-out by sputtered Al-stripes. The FPA is mounted in a dewar and demonstrational thermal images are taken.