Atomic scale nitrogen depth profile control during plasma enhanced atomic layer deposition of high k dielectrics

Abstract

Nitrogen incorporation produces several benefits in the performance of high k gate oxides. However, since too much nitrogen incorporation at the interface of gate dielectric can result in device degradation, the atomic scale control of nitrogen depth profile is desirable. In this study, the authors have improved electrical properties and interface properties by depth profile control of in situ nitrogen incorporation during plasma enhanced atomic layer deposition. The best electrical properties in terms of hysteresis, equivalent oxide thickness, and interface states were obtained when the nitrogen is incorporated in the middle of the thin film, which has not been achievable by other techniques.