Growth and characterization of ≥6” epitaxy-ready GaSb substrates for use in large area infrared imaging applications

In this paper we report on an industry first; the commercial growth and characterization of >/=6" diameter GaSb substrates that are suitable for use in the fabrication of epitaxially grown, large area MWIR-VLWIR detectors. Results will be presented on the production of single crystal >/=6" GaSb ingots grown by a modified version of the Czochralski (LEC) technique, supported by the analysis of bulk material quality by spatial etch pit density assessments with mm resolution. The electrical quality of 6" GaSb crystals will be assessed. Hall mobility, resistivity and carrier level measurements will be made spatially. High quality, epitaxy-ready type surfaces have been prepared and we will demonstrate how the key surface quality characteristics of roughness, oxide thickness and flatness have been maintained across production processes that scale from 4" to ≥6" wafer formats. Comparisons will be made between ≥6" GaSb and other large diameter compound semiconductor materials produced in volume such as GaAs and InP. We conclude by demonstrating that the commercial production of large diameter GaSb substrates has matured and is thus ready to support the full commercialization of GaSb based detector technologies.