An investigation was made of interface states, in HfO2/SiO2/Si(100) systems, that were prepared by using the in situ pulsed laser deposition technique. X-ray photo-electron spectroscopy data revealed that, when the HfO2 film thickness exceeded 11Å, the film composition underwent a systematic change from Hf silicate to O-deficient HfOx<2. It was determined that the evolution of the interface states clearly depended upon the O conditions which were applied during film growth, and that the O vacancy was an important parameter for Hf silicate formation.Role of Oxygen Vacancy in HfO2/SiO2/Si(100) Interfaces. D.Y.Cho, S.J.Oh, Y.J.Chang, T.W.Noh, R.Jung, J.C.Lee: Applied Physics Letters , 2006, 88[19], 193502 (3pp)