Fabrication of High-κ/Ge Stacks with High Quality GeO_2 Interlayer

摘要

Fabrication of high-κ/Ge stacks with high quality interface layer was attempted using the combination of the formation of GeO_2 by low temperature oxidation to avoid GeO desorption at GeO_2/Ge interface and the deposition of component metals of high-κ material followed by O_2 annealing to have ideal V_(FB) value. The results indicate that a more favorable C-V characteristic of Al_2O_3 with GeO_2 as compared to HfO_2. To understand this reason, the interaction between Al_2O_3 or HfO_2 with Ge and GeO_2/Ge using XPS, AFM, SEM and C-V characteristics. The results indicate that the hillocks were formed by the Hf metal diffusion during the thermal treatment.