Lateral quantum dots in Si∕SiGe realized by a Schottky split-gate technique

Abstract

Lateral quantum dots are formed in the two-dimensional electron gases of a high-mobility Si∕SiGe heterostructures by means of split Schottky gates. Palladium gates, defined by e-beam lithography and lift-off, show Schottky barriers with very well controlled leakage currents. At low temperatures we observe Coulomb-blockade and stability diamonds on lateral quantum dots containing a total charge of about 25 electrons. The experiments demonstrate that, in contrast to recent reports, Schottky gates are a feasible approach for the fabrication and integration of single electron transistors in the strained Si∕SiGe heterosystem.