Mega-pixel FPAs in both MWIR and LWIR spectral bands based on Sb strained layer superlattices and nBn epitaxial structures grown on GaSb substrates have recently demonstrated impressive performances at high operating temperatures. An essential component of SLS epitaxial growth initiation is the starting wafer flatness, smoothness and haze. Large diameter GaSb wafers must be manufactured meeting these stringent demands and current state-of-the-art GaSb substrate manufacturing is focused on 100mm wafer diameters. Using a newly developed polishing process, 100mm GaSb substrate manufacturing has resulted in consistent starting wafer peak-to-valley flatness well below 5μm and surface roughness below Rms of 0.2nm. Final substrate and epitaxial wafer Surfscan mapping (<1000/cm² surface defects) and surface roughness (Rms~0.2nm) are presented and compared with measurements of the starting substrates. This paper evaluates the manufacturing and epitaxial growth on 100mm GaSb substrates that have been processed to achieve an MBE grown InAsSb-based nBn MWIR photodetector structure.

Date Published: 31 May 2012
PDF: 6 pages
Proc. SPIE 8353, Infrared Technology and Applications XXXVIII, 835313 (31 May 2012); doi: 10.1117/12.919287

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