Hot electron attenuation of direct and scattered carriers across an epitaxial Schottky interface

TL;DR

This study investigates hot electron transport across an epitaxial NiSi_2/n-Si(111) interface using BEEM, revealing differences in transmission and attenuation lengths between direct and scattered hot electrons, with implications for interface engineering.

Contribution

It provides new insights into the attenuation and transmission behaviors of direct and scattered hot electrons at a NiSi_2/n-Si(111) interface, highlighting the role of inelastic scattering and energy distribution.

Findings

BEEM transmission for scattered hot electrons is significantly lower than for direct hot electrons.

Attenuation length of scattered hot electrons is twice that of direct hot electrons.

Inelastic scattering of hot holes reduces BEEM transmission for scattered hot electrons.

Abstract

Hot electron transport of direct and scattered carriers across an epitaxial NiSi_2/n-Si(111) interface, for different NiSi_2 thickness, is studied using Ballistic Electron Emission Microscopy (BEEM). We find the BEEM transmission for the scattered hot electrons in NiSi_2 to be significantly lower than that for the direct hot electrons, for all thicknesses. Interestingly, the attenuation length of the scattered hot electrons is found to be twice larger than that of the direct hot electrons. The lower BEEM transmission for the scattered hot electrons is due to inelastic scattering of the injected hot holes while the larger attenuation length of the scattered hot electrons is a consequence of the differences in the energy distribution of the injected and scattered hot electrons and the increasing attenuation length, at lower energies, of the direct hot electrons in NiSi_2.