Full-band tunneling in high- κ dielectric MOS structures

Abstract

High- κ oxides such as ZrO 2 and HfO 2 have attracted great interest, due to their physical properties, suitable to replacement of SiO 2 as gate dielectric materials. In this work, we investigate the tunneling properties of ZrO 2 and HfO 2 high- κ oxides, by applying quantum mechanical methods that include the full-band structure of Si and oxide materials. Semiempirical sp 3s∗d tight-binding parameters have been determined to reproduce ab initio band dispersions. Transmission coefficients and tunneling current have been calculated for Si/ZrO 2/Si and Si/HfO 2/Si MOS structures, showing a very low gate leakage current in comparison to SiO 2-based structures with equivalent oxide thickness.