GaAs on 200 mm Si wafers via thin temperature graded Ge buffers by molecular beam epitaxy

Abstract

For heterogeneous integration of III–V compound materials on 200mm Si wafers, we present a complete in-situ molecular beam epitaxy (MBE) process from a Ge strain compensating buffer on Si to GaAs heteroepitaxy. The whole growth process, including high-k gate oxide deposition, is performed in a 200mm MBE cluster tool. Thin (≤0.3μm), temperature-graded Ge buffers are investigated and the influence of the substrate temperature during Ge nucleation and anneals is studied. Using such a buffer, GaAs was grown on 200mm Si wafers and characterized structurally and electrically using MOS capacitors.