Behavior of hydrogen in high dielectric constant oxide gate insulators

Interstitial hydrogen is calculated to act as a shallow donor in the candidate high dielectric constant (k) gate oxides ZrO2, HfO2, La2O3, Y2O3, TiO2, SrTiO3, and LaAlO3 but is deep in the oxides SiO2, Al2O3, ZrSiO4, HfSiO4, and SrZrO3. This may account for the change of sign of fixed charge in oxides, from negative in Al2O3 to positive in HfO2. (C) 2003 American Institute of Physics.