Dependences of effective work functions of TaN on HfO2 and SiO2 on post-metallization anneal

Youhei Sugimoto, Masanari Kajiwara, Keisuke Yamamoto, Yuusaku Suehiro, Dong Wang, Hiroshi Nakashima

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10 Citations (Scopus)

Abstract

We fabricated TaN-gate electrodes on HfO2 and SiO2 films by wet etching using NH4OH/H2O2 solution and investigated the electrical and structural properties of the TaN/SiO2 and TaN/HfO2 interfacial layers. The effective work function (Φm,eff) of TaN on SiO2 and HfO2 are 4.4 and 4.6 eV, respectively. The Φm,eff on SiO2 remained constant after post-metallization anneal (PMA) at temperatures of up to 750 °C and increased after 900 °C, but the Φm,eff on HfO2 increased after PMA at 750 °C. The analysis by X-ray photoelectron spectroscopy (XPS) indicated that Ta oxide was formed near the TaN/SiO2 and TaN/HfO2 interfacial layers after the annealing at 900 °C. It was concluded that the Φm,eff instability is strongly associated with the Ta-O bond formation at the interfaces.

Original languageEnglish
Pages (from-to)204-206
Number of pages3
JournalThin Solid Films
Volume517
Issue number1
DOIs
Publication statusPublished - Nov 3 2008

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Materials Chemistry

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