Comparison of the Physical and Electrical Properties of HfO₂/Al₂O₃/HfO₂/GeO/Ge and HfO₂/Al₂O₃/GeO/Ge Gate Stacks.

A high-quality HfGeO interfacial layer (IL) was formed in a HfO₂/Al₂O₃/HfO₂/GeO gate stack through thermal annealing. The diffusing of GeO into the HfO₂ layer led to the mixing of the GeO and HfO₂ layers, as identified through energy-dispersive X-ray Spectroscopy (EDX). X-ray photo-electron spectroscopy (XPS) data for HfGeO IL confirmed the formation of Ge-O-Hf bonds owing to the induced shift of the Ge3d spectra to lower binding energies.