Effects of interlayer and annealing on chemical states of HfO_(2) gate insulators studied by photoemission spectroscopy

摘要

We have performed photoemission spectroscopy of high-k gate insulators HfO_(2)/HfSiON/Si to investigate the interlayer formation by Hf metal predeposition and the annealing effect systematically. Comparing the line shapes of core-level photoemission spectra for two systems with and without Hf-metal predeposition, we found that Hf-metal predeposition effectively reduces the growth of interface layer. Hf 4f core-level spectra revealed that the annealing at 1000℃ for both samples causes the formation of the metallic Hf and Hf-silicide clusters. Surface morphology was also observed by atomic force microscopy.