SBIR-STTR Award

Special technology and circuit architecture is under investigation for implementation of low power electronics (LPE) that operate at low supply voltages without sacrificing performance. GaSb substrates have advantages that make it attractive for applications that require low power and high frequency. A significant aspect inhibiting commercial application of GaSb wafers is the inconsistency of the substrate surface for heterostructure growth and device applications. In particular, producing a damage free surface with a designed surface oxide is difficult in this soft material using standard chemical-mechanical polishing (CMP) techniques. An opportunity exists to establish a production method for obtaining smooth GaSb surfaces with a controlled oxide. Gas cluster ion beam (GCIB) processing, a novel nanoscale surface modification technique, will be used to smooth and remove surface and sub-surface damage from polished two-inch (100) GaSb wafers. A GCIB matrix of as-received and smoothed GaSb surfaces will be examined using MBE desorption and heteroepitaxy growth. Structural and Electrical integrity of the substrates will be analyzed to determine feasibility. Commercialization of the GaSb substrate surface preparation process is regarded with high probability. The nation may expect to benefit from the success of the proposal to quickly establish a commercial source of epi-ready GaSb wafers for both industry and the government. Commercialization of GaSb substrates for low power applications will be greatly enhanced by the robotic, environmental friendly GCIB process with a United States manufacturing base for GCIB instrumentation 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.

Keywords:
JOINT STRIKE FIGHTER, HOMELAND SECURITY, FOCAL PLANE ARRAY, NEXT-GENERATION TELECTOMMUNICATION TECHNOLOGY, ANTIBALLISTIC-SATELLITE, INSB, GASB, STEALT