Enhanced conductance of chlorine-terminated Si(111) surfaces: Formation of a two-dimensional hole gas via chemical modification

Abstract

Chlorine termination of low-doped, $n$-type Si(111) is found to lead to an increase in conductance relative to the hydrogen-terminated surface. This increase is attributed to formation of an inversion layer due to the strongly electron withdrawing character of the chemisorbed chlorine. The presence of this inversion layer is confirmed by high resolution electron energy loss spectroscopy and Hall effect measurements. Electron beam irradiation destroys the inversion layer, suggesting a route to nanoscale patterning of this 2D hole gas.