Relationships among equivalent oxide thickness, nanochemistry, and nanostructure in atomic layer chemical-vapor-deposited Hf-O films on Si

The relationship among the equivalent oxide thickness (EOT), nanochemistry and nanostructure of atomic layer chemical-vapor-deposited (ALCVD) Hf-O-based films, with oxide and nitrided oxide interlayers on Si substrate using X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM), scanning transmisson electron microscopy (STEM) was studied. The XPS studies indicated the formation of Hf-O-Si bonds in as-deposited amorphous films, the amount of which was influenced by the interlayer composition and annealing conditions. A three-layer capacitor model was used to determine the respective contributions to the measured EOT. The electric permittivity of the interlayer was found to be 0.06.