High conductance Ge p-channel heterostructures realized by hybrid epitaxial growth

摘要

Strained Ge p-channel heterostructures have been realized by hybrid-epitaxial growth. Strain-tuning Si_(0.4)Ge_(0.6) virtual substrates were grown by ultra-high vacuum chemical vapour deposition and active layers were deposited by solid-source molecular beam epitaxy at low temperature. Following ex situ annealing, Hall effect measurements revealed a hole mobility of 1900 cm~2 V~(-1) s~(-1) at 300 K (27 000 cm~2 V~(-1) s~(-1) at 10 K), with a density of 1.8 x 10~(12) cm~(-2), giving a conductance in excess of current Ge heterostructures. Using a maximum-entropy mobility-spectrum analysis, 1.0 x 10~(12) cm~(-2) of these holes were found to have a mobility of 2700 cm~2 V~(-1) s~(-1) at 300 K.