Fluctuations of the Au-Si(100) Schottky barrier height

Abstract

Schottky barrier height fluctuations of Au films on Si(100) are directly imaged with nm-scale resolution by ballistic electron emission. Fluctuations are made visible by using a highly doped (${\mathit{N}}_{\mathit{d}}$\ensuremath{\approxeq}${10}^{17}$ ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}3}$) substrate. Randomly distributed (approximately ${10}^{13}$ ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}2}$) spots (about 2 nm in diameter) of reduced barrier height (typical \ensuremath{\Delta}\ensuremath{\Phi}=20--50 meV) are observed. The microscopic distribution of barrier heights effective in emission is consistent with mean barrier height values measured by standard techniques.