Tight Distribution of Dielectric Characteristics of HfSiON in Metal Gate Devices

Abstract

Leakage current characteristics with significantly reduced dispersion were achieved for HfSiON gate dielectric film by selecting TiN gate electrode with low reactivity, compared to the conventional poly-Si gate. The breakdown lifetime and its characteristic homogeneity were also enormously improved. With intensive study on these electrical characteristics, it was concluded that the concentration of oxygen vacancy was significantly reduced, giving rise to the homogeneity improvement. Moreover, we have shown an explanation for the dielectric breakdown in terms of oxygen transport in the Hf-based dielectric film.