Effects of Antimony Deposition on Field-Emission Current Density of Ge/Si

Abstract

To estimate the field-emission current density of a germanium/silicon heterosystem, 20-nm Ge/Si(100) were grown by molecular beam epitaxy. The surface of one sample was covered with a layer of antimony, which was removed in vacuum prior to the samples being measured. A second sample of Ge/Si was exposed to room air in the absence of antimony. The current-voltage characteristics of both samples obtained by scanning tunneling microscopy were discovered to be in agreement with classical Fowler-Nordheim theory. The density of emission current from Ge nanocrystal exceeds the density of emission current from the wetting layer of Ge/Si. The density of emission current of pure Ge nanocrystal is less than the density of emission current of Ge nanocrystal with adsorption layers.