Schottky barrier and attenuation length for hot hole injection in non-epitaxial Au on p-type GaAs

摘要

Ballistic electron emission microscopy (BEEM) was performed to obtainnanoscale current versus bias characteristics of non-epitaxial Au on p-typeGaAs in order to accurately measure the local Schottky barrier height. Holeinjection BEEM data was averaged from thousands of spectra for various metalfilm thicknesses and then used to determine the attenuation length of theenergetic charge carriers as a function of tip bias. We report the markedincrease in attenuation length at biases near the Schottky barrier, providingevidence for the existence of coherent BEEM currents in Schottky diodes. Theseresults provide additional evidence against the randomization of a chargecarrier's momentum at the metal-semiconductor interface.