Electrical and structural properties of group-4 transition-metal nitride (TiN, ZrN, and HfN) contacts on Ge

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

Electrical and structural properties were investigated for group-4 transition-metal nitride contacts on Ge (TiN/Ge, ZrN/Ge, and HfN/Ge), which were prepared by direct sputter depositions using nitride targets. These contacts could alleviate the intrinsic Fermi-level pinning (FLP) position toward the conduction band edge. It was revealed that this phenomenon is induced by an amorphous interlayer (a-IL) containing nitrogen atoms at the nitride/Ge interfaces. The strength of FLP alleviation positively depended on the thickness of a-IL. TiN/Ge and ZrN/Ge contacts with ∼2 nm-thick a-ILs showed strong FLP alleviations with hole barrier heights (ΦBP) in the range of 0.52-56 eV, and a HfN/Ge contact with an ∼1 nm-thick a-IL showed a weaker one with a ΦBP of 0.39 eV. However, TaN/Ge contact without a-IL did not show such FLP alleviation. Based on the results of depth distributions for respective elements, we discussed the formation kinetics of a-ILs at TiN/Ge and ZrN/Ge interfaces. Finally, we proposed an interfacial dipole model to explain the FLP alleviation.

Original languageEnglish
Article number115701
JournalJournal of Applied Physics
Volume118
Issue number11
DOIs
Publication statusPublished - Sep 21 2015

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

Fingerprint Dive into the research topics of 'Electrical and structural properties of group-4 transition-metal nitride (TiN, ZrN, and HfN) contacts on Ge'. Together they form a unique fingerprint.

  • Cite this