As an alternative to the traditional liquid phase epitaxy (LPE) for HgCdTe (MCT) fabrication, molecular beam epitaxy (MBE) technology has generated a great amount of interest for well over two decades. MBE promises improved layer quality in terms of homogeneity, availability of large-area, inexpensive alternative substrates, and the possibility to fabricate 3^rd generation infrared detectors. The question about the most suitable alternative substrate has not been answered conclusively to date. AIM has focused its MCT growth efforts on the (211)B GaAs substrate which has received comparatively little attention in the last years. In this paper we present the state of MBE technology at AIM. We will describe the MBE growth and material quality of MCT on (211)B GaAs. Electro-optical characterization of focal plane arrays (FPAs) of detectors with cut-off wavelengths in both the mid- and long-wavelength (MW and LW) IR regions will be shown. The FPAs (640 x 512 pixels with 15 μm pitch) have been processed by AIMs standard planar n-on-p technology. For a MWIR detector, a low NETD of 18.3 ± 2.0 mK at 99.31% pixel operability has been achieved. The promising results in both wavelength regions illustrate the potential of (211)B GaAs as alternative substrate for MCT growth.

Date Published: 31 May 2012
PDF: 7 pages
Proc. SPIE 8353, Infrared Technology and Applications XXXVIII, 83532Q (31 May 2012); doi: 10.1117/12.919989

Published in SPIE Proceedings Vol. 8353:
Infrared Technology and Applications XXXVIII
Bjørn F. Andresen; Gabor F. Fulop; Paul R. Norton, Editor(s)