Non-Contact Final Polish/Passivation Technology for the Production of Epi-Ready InSb and GaSb Wafers

Special technology and circuit architecture is under investigation for implementation of high performance, infra-red, and low power electronics technology. InSb and GaSb substrates have advantages that make them attractive and in use for high frequency stealth (such as the joint strike fighter) and commercial applications. A significant aspect inhibiting ready-to-use implementation of these wafers is the inconsistency of the substrate surface. In particular, producing epi-ready surfaces with a desorbable oxide is difficult when using standard chemical-mechanical polishing (CMP) finishing technique. The Phase I program demonstrated a 33% to 65% reduction in average roughness (Ra) and peak-to-valley (Z) roughness of InSb and GaSb surfaces through use of gas cluster ion beam (GCIB) smoothing processes prior to homoepitaxy growth. A controlled oxide and the elimination of surface pitting in substrate/epitaxy interfaces with molecular beam homoepitaxy application were observed. In the Phase II program, highly precise InSb and GaSb substrate alignment (±0.01°), a consistent surface RHEED oscillation pattern, and explicit electrical integrity of InSb based focal plane arrays made from the improved substrates will be implemented to provide verification of "epi-readiness" and determine substrate specifications. Enhanced commercialization of these wafer specification GaSb and InSb substrates is regarded with high probability.