Nitrogen Incorporation into Hafnium Oxide Films by Plasma Immersion Ion Implantation

The physics and effects of nitrogen incorporation into hafnium oxide (HfO2) films were studied in detail. We found that only a trace amount (∼5%) of nitrogen can be introduced into the HfO2 films by plasma immersion ion-implantation, regardless of implantation dose. We proposed that the nitrogen incorporation is mainly due to the filling of O vacancies in the as-deposited HfO2 films and the nitridation of silicide bonds at the HfO2/Si interface. Temperature-dependent capacitance–voltage and current–voltage characteristics measurements indicate that both interface and oxide trap densities were greatly reduced as the results of the nitrogen filling of the O-vacancies and the nitridation of interfacial hafnium silicide bonds.