First-principles calculations were made of the energy levels of the oxygen vacancy

in La2O3, Lu2O3 and LaLuO3. The levels were found to lie above the Si gap when

aligned using the experimental band offsets. In hexagonal La2O3, Lu2O3 and

LaLuO3, oxygen vacancies with four neighbours behaved similarly to those in

HfO2, which were identified as the main electron trap, while oxygen vacancies with

six neighbours had no negative charged state so that they were less important for

charge-trapping. Oxygen vacancies in perovskite LaLuO3 had only a positive

charge state and so did not act as electron traps.

Oxygen Vacancies in High Dielectric Constant Oxides La2O3, Lu2O3, and LaLuO3.

K.Xiong, J.Robertson: Applied Physics Letters, 2009, 95[2], 022903. See also:

Microelectronic Engineering, 2009, 86[7-9], 1672-5