Photoemission induced bias in two-dimensional silicon pn junctions

Abstract

Spectroscopic x-ray photoelectron emission microscopy was used to study the role of the pn junction on imaging of micron scale n- and p-doped silicon patterns epitaxially grown on p- and n-type substrates, respectively. In the closed n-doped patterns, contrast with respect to open patterns is observed in both work function and Si 2p binding energy. Reverse bias at the junction creates a shift of electrical potential induced by photoemission in the closed patterns. No shift is observed for p-doped patterns on n substrate, pointing to the importance of doping combination and pattern geometry in the contrast observed in electron microscopy.