Numerical Foundation of Hot-Electron Diffraction Experiment Based on Ballistic Electron Emission Microscope

Abstract

We provide the numerical foundation for a previously proposed experiment in hot-electron diffraction observation in solids based on the ballistic electron emission microscope (BEEM). It is found that the hot-electron wave function in a semiconductor becomes a quasi-spherical wave because of a large refraction effect at the base metal/semiconductor interface due to the large discontinuities between the conduction band bottoms and effective masses of the materials. Thus, it has been clarified that the quantum reciprocity, our measurement principle, can be applied to our proposed experimental configuration by using BEEM. We have also carried out numerical simulations for our experiment with a π-phase shifter structure as a wave front modulator by using the finite difference time domain (FDTD) method. The results showed diffraction patterns with high contrast, and thus our approach to hot-electron diffraction observation was affirmed.