Specific Contact Resistivity Reduction Through Ar Plasma-Treated TiO2−x Interfacial Layer to Metal/Ge Contact

We demonstrate contact resistivity reduction by inserting an Ar plasma-treated TiO
_2-x
heavily doped interfacial layer to metal/semiconductor contact to overcome a Fermi-level pinning problem on germanium (Ge). A specific contact resistivity of 3.16 × 10
^-3
Ω · cm
²
on moderately doped n-type Ge substrate (6 × 10
¹⁶
cm
^-3
) was achieved, exhibiting ×584 reduction from Ti/Ge structure, and ×11 reduction from Ti/undoped TiO
₂
/Ge structure. A novel doping technique for TiO
₂
interfacial layer at low temperature using Ar plasma was presented to lower S/D contact resistance in Ge n-MOSFET.