The HfSi_xO_y Interfacial Layer Effect on Improving Electrical Characteristics of Ultrathin High-K TiO_2 Gate Dielectric

摘要

We report significant improvement of the electrical characteristics of high-quality titanium oxide (TiO_2) with hafnium silicate (HfSi_xO_y) as an interfacial layer as the gate dielectrics in a metal oxide semiconductor (MOS) structure. Compared with conventional chemical oxide and oxynitride as interfacial layers, TiO_2 /HfSi_xO_y exhibited excellent electrical characteristics such as a lower leakage current density of 3 X 10~(-5) A/cm~2 at a gate bias of -1 V below flatband voltage under an equivalent oxide thickness of 10.8 A and low interface trap sites monitored by the conductance loss peak characteristics. Based on its excellent electrical characteristics. TiO_2 /HfSi_xO_y is a promising alternative gate dielectric for future MOS field effect transistor device applications.