Evaluation of tantalum silicon alloy systems as gate electrodes

H. Luan*, Husam Niman Alshareef, P. S. Lysaght, H. R. Harris, H. C. Wen, K. Choi, Y. Senzaki, P. Majhi, B. H. Lee

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

5 Scopus citations

Abstract

The effect of Si concentration on the effective work function of tantalum silicon (Ta-Si) alloy systems as gate electrodes in direct contact with Si O2 and HfSi Ox gate dielectrics has been studied extensively. It was found that the Si concentration in the Ta-Si electrodes (≥60 at. % Si) has a strong effect on the effective work function, and three discrete composition-dependent phases (tantalum metal, tantalum silicide, and silicon) coexist in the films. The film resistivity and density also change dramatically as a function of Si concentration. Physical analysis shows that these Si-rich Ta-Si electrodes are amorphous at room temperature and crystallize with a 1000 °C, 5-s anneal. Finally, an effective work function value of 3.98 eV has been achieved by arsenic implantation of a capacitor electrode layer in Ta-SiHfSi Ox film systems, thereby producing a potential n -type metal gate electrode in conjunction with high- k gate dielectrics.

Original languageEnglish (US)
Article number212110
Pages (from-to)1-3
Number of pages3
JournalApplied Physics Letters
Volume87
Issue number21
DOIs
StatePublished - Nov 25 2005

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

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