%0 Journal Article
%T Investigation of Mobility Limiting Mechanisms in Undoped Si/SiGe Heterostructures
%A X. Mi
%A T. M. Hazard
%A C. Payette
%A K. Wang
%A D. M. Zajac
%A J. V. Cady
%A J. R. Petta
%J Physics
%D 2015
%I arXiv
%R 10.1103/PhysRevB.92.035304
%X We perform detailed magnetotransport studies on two-dimensional electron gases (2DEGs) formed in undoped Si/SiGe heterostructures in order to identify the electron mobility limiting mechanisms in this increasingly important materials system. By analyzing data from 26 wafers with different heterostructure growth profiles we observe a strong correlation between the background oxygen concentration in the Si quantum well and the maximum mobility. The highest quality wafer supports a 2DEG with a mobility of 160,000 cm^2/Vs at a density 2.17 x 10^11/cm^2 and exhibits a metal-to-insulator transition at a critical density 0.46 x 10^11/cm^2. We extract a valley splitting of approximately 150 microeV at a magnetic field of 1.8 T. These results provide evidence that undoped Si/SiGe heterostructures are suitable for the fabrication of few-electron quantum dots.
%U http://arxiv.org/abs/1503.05862v1