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

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
$\hbox{1.3} \times \hbox{10}^{-6}\ \Omega\cdot\hbox{cm}^{2}$
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.