In this letter, we discuss the mechanism of Schottky barrier height (SBH) modulation of the TaN/Ge contact by varying the nitrogen concentration in the TaN. The Fermi level, which is strongly pinned near the valence band edge of Ge, moves to the conduction band edge of Ge with higher nitrogen concentration in the reactive sputtered TaN. This SBH modulation is attributed to the presence of an electric dipole induced by Ge-N bonds at the interface of the TaN/Ge contact. This SBH modulation due to the semiconductor-nitrogen bonds at the interface is not specific to TaN/Ge, but rather is a general feature in various transition-metal nitride systems on various semiconductors.
Bibliographical noteFunding Information:
This work was supported by the Korea Evaluation Institute of Industrial Technology within the Technology Innovation Program through the Ministry of Trade, Industry and Energy, Korea, under Grant 10048594. The review of this letter was arranged by Editor J. Cai.
© 2015 IEEE.
- Fermi level de-pinning
- Schottky barrier height
- tantalum nitride
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering