Formation of Low-Resistivity Nickel Germanide Using Atomic Layer Deposited Nickel Thin Film

Abstract

Nickel germanide (NiGe) was formed from atomic layer deposition (ALD) Ni on Ge and a subequent annealing process; the Ni film with low resistivity ( $34~\mu \Omega \cdot \text {cm}$ ) at 15 nm was obtained by N2 + H2 plasma treatment after Ni precursor injection. The formed NiGe film showed low specific contact resistivity ( $\rho _{c})$ values of 9.01 $\mu \Omega \cdot \text {cm}^{2}$ for an NiGe/n+Ge contact and 3.61 $\mu \Omega \cdot \text {cm}^{2}$ for an NiGe/p+Ge contact. These values were comparable to those obtained using sputtered Ni. In addition, the ALD process-based NiGe showed excellent thermal/electrical stability up to 600 °C.