Automated Wafer Polishing for Epi-ready Antimony-based Substrate Materials

EPIR Technologies demonstrated in Phase I of this project the ability to polish small GaSb wafers to an epi-ready state. Surfaces smoother than those of typical wafers sold by the best supplier of GaSb substrates for SL growth were obtained. In Phase II, we propose to build upon the experience gained in Phase I to establish a more automated polishing procedure to consistently obtain even smoother GaSb surfaces on large 50 mm diameter wafers. We also will obtain virtually flat substrate surfaces and expect to be able to maintain the ideal 1:1 surface stoichiometry desired for MBE growth. Using a variety of nondestructive characterization tools, the surface chemistry associated with different chemical polishing agents and etchants will be intensively investigated in order to further optimize our successful proprietary chemical polishing protocols developed during the Phase I program. As the final and most important test of the quality of the polished surfaces, both InGaSb/InAs superlattices and devices built on them will be grown and extensively characterized.