Determination of the energetic resolution of Schottky barrier visualization via interface band structure and parallel momentum conservation

Abstract

The energetic resolution of Schottky barrier visualization is determined by utilizing differences in interface band structures between the Au/Si(001) and Au/Si(111) non-epitaxial interfaces and parallel momentum conservation of the carriers. The visualization technique is based on ballistic electron emission microscopy and spectroscopy, where tens of thousands of spectra are collected on a grid and then fit to extract a spatially resolved map and histogram of the electrostatic barrier height. A resolution of 10 meV is determined from the minimal splitting and eventual merging of the histograms as the gold thickness decreases for the Au/Si(001) and Au/Si(111) samples. This splitting is below previously measured differences in barrier heights extracted from computational modeling of measured barrier height distributions from other interfaces.

Phase-space ab-initio direct and reverse ballistic-electron emission spectroscopy: Schottky barriers determination for Au/Ge(100)

“…When the electron's kinetic energy e | V | of the injected electrons is higher than the local Schottky barrier formed between the metal and the semiconductor, the electrons can overcome the local barrier and a current I b is transmitted across the sample and collected through the backside Ohmic contact (Figure 1-a) (Wu et al, 2013;Janardhanam et al, 2019). Accurate Ballistic Electron Emission Spectroscopy (BEES) determination for the Schottky threshold Φ relies on a best-fit where experimental measurements are compared with a theoretical model where currently the state-of-the-art standard claims accuracies between 10 and 30 meV Rogers et al, 2021). Such a procedure has been successfully used before in other fields, like structural work related to diffraction techniques, and requires the use of theory as accurate as possible and free of adjustable parameters to avoid spurious correlations in the determination of the value of Φ.…”