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Volume 113, Issue 18, 14 May 2013
113(2013); http://dx.doi.org/10.1063/1.4804059View Description Hide Description
The out diffusion of As is considered as one of the key issues of GaAs-based devices. We performed first-principles calculation to study the electronic structure distortion of HfO2 induced by out-diffused As. As diffused into oxygen vacancy of HfO2 results in several gap states ranging from 1.38 eV to 2.33 eV above HfO2 valence band maximum through As 4p and Hf 5d interaction; on the other hand, interstitial As not only introduces two gap states but also donates one electron to the conduction band of HfO2. These findings provide an interpretation for the degraded electrical performance of dielectrics on GaAs.