Application of spectroscopic photoemission and low energy electron microscope to high-k gate dielectrics: Relationship between surface morphology and electronic states during Hf-silicide formation

We have applied the spectroscopic photoemission and low energy electron microscope to study high-k gate dielectrics and have performed the following in situ operations during ultrahigh vacuum annealing: real-time observation of surface morphology and microregion photoelectron spectroscopy measurements. Changes in surface morphology and electronic states were consistent with the models previously reported in the case of HfO₂/Si. No clear differences between void regions and nonvoid regions have been observed in microregion photoelectron spectra for poly-Si/HfO₂/Si, regardless of phase separation in real space. These results have suggested that the initial void formation occurs in about 100-nm wide regions for both HfO₂/Si and poly-Si/HfO₂/Si.