Low temperature fabrication and characterization of nickel germanide Schottky source/drain contacts for implant-less germanium p-channel metal-oxide-semiconductor field-effect transistors

摘要

In this work, nickel germanide Schottky contacts have been fabricated en n-type germanium (n-Ge) with an optimum barrier height of 0.63 eV. For rapid thermal annealing (RTA) temperatures above 300 ℃, all phases of nickel and germanium convert to nickel mono-germanide (NiGe). However, higher RTA temperatures are also found to cause agglomeration of the NiGe phase and higher leakage current. So, the optimum temperature for Schottky-based source/drain contact formation on n-Ge is ~300℃, where the nickel mono-germanide phase is formed but withoutphase agglomeration.