Interfacial, optical properties and band offsets of HfTiON thin films with different nitrogen concentrations

M. Liu, M. Fang, X. J. Wang, Y. Y. Luo, H. M. Wang, S. H. Kang, L. D. Zhang, Q. Fang

Research output: Contribution to journalArticlepeer-review

6 Scopus citations

Abstract

The effect of nitrogen concentration on the interfacial and optical properties, as well as band offsets of HfTiO thin films by rf sputtering HfTi alloy target has been systematically investigated. The results indicate that an interfacial layer is unavoidably formed between HfTiON thin films and Si substrate, and the main content of the interfacial layer is silicate. No silicide is formed in the interfacial layer which is partly responsible for the poor electrical properties of high-k gate dielectrics. The optical properties of HfTiON films change, such as the refractive index decreases, while the extinction coefficient increases with the increase of N content, due to the defects increase in the films. The results also indicate that the bandgap and VB offset reduce with the introduction of N into HfTiO thin films. The CB offset of the HfTiON thin films is almost unchanged indicating that the N concentration has little effect on CB offset. However, the bandgap and band offsets are all higher than 1 eV, the sufficient band offsets still makes sputtering-derived HfTiON films by HfTi alloy target a promising high-k gate dielectric for future complementary metal oxide semiconductor technology.

Original languageEnglish
Article number024110
JournalJournal of Applied Physics
Volume110
Issue number2
DOIs
StatePublished - Jul 15 2011
Externally publishedYes

Scopus Subject Areas

  • General Physics and Astronomy

Fingerprint

Dive into the research topics of 'Interfacial, optical properties and band offsets of HfTiON thin films with different nitrogen concentrations'. Together they form a unique fingerprint.

Cite this