The dielectric properties and bias temperature instability characteristics of in situ nitrogen incorporated ZrOxNy gate dielectrics were compared with those of ZrO2, HfO2, and HfOxNy. ZrOxNy showed a much smaller capacitance equivalent oxide thickness (1.43 nm) than ZrO2 (2.13 nm) and exhibited a turn-around effect under a positive gate stress bias in n-type metal oxide semiconductor field-effect transistor, which is consistent with HfOxNy. However, compared to HfOxNy, ZrOxNy showed a significantly lower initial V-th shift under a positive gate stress bias due to the lower number of shallow bulk traps related to oxygen vacancies. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3456518] All rights reserved.