Hetero-integration of GaSb channel on silicon with ultra-thin buffer utilizing interfacial misfit dislocations

Abstract

III–V semiconductors have attracted considerable interest as channel material in the transistor applications due to their relatively high carrier mobility compared to silicon. Among III–V semiconductors, GaSb and InAs are particularly interested due to their high hole mobility (1000 cm2V−1s−1) and electron mobility (40000 cm2V−1s−1), respectively. Furthermore, small lattice mismatch between GaSb and InAs benefit the integration of both materials on a single platform for pFET and nFET applications, respectively. However, large lattice mismatch between both materials and silicon poses a great challenge to integrate both materials on silicon platform. The problem of large lattice mismatch could be overcome by hetero-integration of III–V semiconductors on silicon substrate. Several hetero-integration methods such as aspect ratio trapping and thick graded buffer have been reported. In this report, we report hetero-integration of GaSb directly on Si substrate using self-assembled interfacial misfit (IMF) dislocations to relieve large lattice strain between GaSb and Si.