Reduction in Specific Contact Resistivity to $ \hbox{n}^{+}$ Ge Using $\hbox{TiO}_{2}$ Interfacial Layer

Abstract

We report a metal-insulator-semiconductor (MIS) contact using a TiO2 interfacial layer on highly doped n+ Ge to overcome the problem of metal-Fermi-level pinning on Ge, which results in a large electron barrier height. A specific contact resistivity of 1.3 × 10-6 Ω·cm2 was achieved, which represents a 70× reduction from conventional contacts. For the first time, interfacial layer conductivity is experimentally identified as an important consideration for high-performance MIS contacts. New insights on the mechanism responsible for contact resistance reduction are presented.