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

摘要

We report a metal–insulator–semiconductor (MIS) contact using a $hbox{TiO}_{2}$ interfacial layer on highly doped $hbox{n}^{+}$ 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 $hbox{1.3} times hbox{10}^{-6} Omegacdothbox{cm}^{2}$ was achieved, which represents a 70 $times$ 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.