STM-Induced Hydrogen Desorption via a Hole Resonance

Abstract

We report STM-induced desorption of H from $\mathrm{Si}\left(100\right)\ensuremath{-}\mathrm{H}\left(2\ifmmode\times\else\texttimes\fi{}1\right)$ at negative sample bias. The desorption rate exhibits a power-law dependence on current and a maximum desorption rate at $\ensuremath{-}7\mathrm{V}$. The desorption is explained by vibrational heating of H due to inelastic scattering of tunneling holes with the Si-H $5\ensuremath{\sigma}$ hole resonance. The dependence of desorption rate on current and bias is analyzed using a novel approach for calculating inelastic scattering, which includes the effect of the electric field between tip and sample. We show that the maximum desorption rate at $\ensuremath{-}7\mathrm{V}$ is due to a maximum fraction of inelastically scattered electrons at the onset of the field emission regime.