Oxygen vacancies in high-k oxides
2007; Elsevier BV; Volume: 84; Issue: 9-10 Linguagem: Inglês
10.1016/j.mee.2007.04.020
ISSN1873-5568
AutoresK. Tse, Dameng Liu, K. Xiong, John Robertson,
Tópico(s)Ferroelectric and Negative Capacitance Devices
ResumoHigh dielectric constant (K) gate oxides such as HfO2 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.
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