Thermal Processing Impact on the Integrity of HfO2-Based High-k Gate Dielectrics

Comprehensive studies of the integrity of HfO2-based high-k gate dielectrics are critical for optimizing and determining their performance properties. We present our results of atomic force microscopy, angle-resolved X-ray photoelectron spectroscopy, mercury probe, secondary ion mass spectrometry, and X-ray diffraction investigations of the HfO2 gate stack integrity thermally processed with low and high temperatures, and the arising issues on interfacial reaction, diffusion, crystal phase, surface structures, impurities, and dielectric behaviors are addressed and discussed. The aim of the present study is to gain a better understanding of these physical, chemical, and structural characteristics of high-k oxide gate dielectric stacks on silicon under elevated temperature annealing.