Temperature dependence of contact resistance of Au-Ti-Pd2Si-n+-Si ohmic contacts

TL;DR

This study examines how the contact resistance of Au-Ti-Pd2Si ohmic contacts to heavily doped n+-Si varies with temperature, revealing conduction through metal shunts and diffusion as key factors.

Contribution

It proposes a mechanism for contact resistance formation involving metal shunts and diffusion, applicable to wide-gap semiconductors with surface states and dislocations.

Findings

Contact resistance increases with temperature due to conduction through metal shunts.

Diffusion input of electrons limits the contact resistance.

Proposed mechanism may apply to wide-gap semiconductors with high surface state density.

Abstract

We investigated temperature dependence of contact resistance of an Au-Ti-Pd2Si ohmic contact to heavily doped n+-Si. The contact resistance increases with temperature owing to conduction through the metal shunts. In this case, the limiting process is diffusion input of electrons to the metal shunts. The proposed mechanism of contact resistance formation seems to realize also in the case of wide-gap semiconductors with high concentration of surface states and dislocation density in the contact.