Oxygen vacancies in high-k oxides

✍ Scribed by K. Tse; D. Liu; K. Xiong; J. Robertson

• Book ID: 104051720
• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 628 KB
• Volume: 84
• Category: Article
• ISSN: 0167-9317
• DOI: 10.1016/j.mee.2007.04.020

✦ Synopsis

High dielectric constant (K) gate oxides such as HfO 2 have suffered from charge trapping, threshold voltage shifts and a difficulty of metal or poly-Si gates to achieve band edge work function values. We investigate how these are related to the oxygen vacancies in a series of ab-initio calculations. The O vacancy is found to correlate with optical, luminescence and charge pumping spectra. The O vacancy contributes to the Fermi level pinning effect, which limits the band edge work functions. Inhibiting motion of vacancies may allow less pinning of gate electrode work functions.