Low temperature tunneling current enhancement in silicide/Si Schottky contacts with nanoscale barrier width

TL;DR

This study investigates low temperature tunneling currents in silicide/Si Schottky contacts, revealing how nanoscale barrier widths and dopant segregation influence electrical behavior and current enhancement.

Contribution

It introduces a detailed analysis of tunneling current enhancement at low temperatures using non-equilibrium Green's function simulations, highlighting effects beyond traditional thermionic-field emission models.

Findings

Excess low-temperature current occurs in short or dopant-segregated contacts at high voltages.

Barrier profile dependence on voltage explains deviations from classical models.

Nanoscale barrier width significantly impacts tunneling current behavior.

Abstract

The low temperature electrical behavior of adjacent silicide/Si Schottky contacts with or without dopant segregation is investigated. The electrical characteristics are very well modeled by thermionic-field emission for non-segregated contacts separated by micrometer-sized gaps. Still, an excess of current occurs at low temperature for short contact separations or dopant-segregated contacts when the voltage applied to the device is sufficiently high. From two-dimensional self-consistent non-equilibrium Green's function simulations, the dependence of the Schottky barrier profile on the applied voltage, unaccounted for in usual thermionic-field emission models, is found to be the source of this deviation.