Room-temperature Transport Properties of High Drift Mobility Two-dimensional Electron Gas Confined in a Strained Si Quantum Well

Abstract

The drift mobility, carrier density and conductivity of the two-dimensional electron gas (2DEG) confined in the tensilely strained 15 nm Si quantum well (QW) of SiGe heterostructures were obtained by mobility spectrum analysis at room-temperature. The highest 2DEG drift mobility of 2900 cm2 V-1 s-1 with carrier density of 1×1011 cm-2 were observed in the Si QW with -0.9% tensile strain. However, the increase of strain up to -1.08% resulted in the decline of 2DEG drift mobility down to 2670 cm2 V-1 s-1 and the pronounced increase of carrier density up to 4.4×1011 cm-2. Nevertheless, the pronounced enhancement of 2DEG conductivity was observed.