Effect of Hf-N bond on properties of thermally stable amorphous HfSiON and applicability of this material to sub-50nm technology node LSIs

The electric and structural properties of hafnium silicon oxynitride (HfSiON) with high Hf/(Hf+Si) (35/spl sim/100%) were investigated, focusing on the role of Hf-N bonds inside the material. The results show that the existence of Hf-N bonds in the films result in a high dielectric constant and high thermal stability. Using ultra-thin HfSiON with high Hf and high N concentrations, thermally stable amorphous high-k stacks with EOT of 0.6 nm and with 10/sup -5/ times Jg reduction, relative to that in SiO/sub 2/ was obtained.