Morphological Structure Of Films Research Articles

Simultaneously-doping of HfO2 thin films by Ni with sputtering technique and effect of post annealing on structural and electrical properties

This article reports a detailed structural and electrical characterization study of Ni:HfO2 dielectrics grown by rf and dc sputtering and variations in the rapid thermal annealing temperature. Annealing produced obvious changes in the morphological structure of films and XRD confirmed that the crystallite size increased from 1.3 nm to 14.4 nm with the annealing temperature. XPS showed that the amount of non-lattice oxygen decreased owing to the effects of annealing and resistivity. Dc resistivity measurements showed that the lowest sheet resistance of 1.182 × 106 Ω/□ was achieved by as-deposited films and increased to 70.960 Ω/□ with annealing. Structural differences in films due to the effect of annealing caused equivalent circuit models to vary and different resistance values in electrochemical impedance spectrometry. This study illustrates that HfO2 thin films, boosted by doping and rapid thermal annealing, provide a route toward advanced gate oxide stack structures in electronic devices beyond conventional high-dielectric-constant materials.

Morphological Structure Characterization of PAH/NiTsPc Multilayer Nanostructured Films

Morphological structure and growth process of LbL nanostructured films from nickel tetrasulfonated phthalocyanine (NiTsPc) alternated with polyallylamine hydrochloride (PAH) were investigated. The experimental results of UV-visible adsorption kinetics (modeled by Johnson-Mehl-Avrami functions) and AFM images analyzes suggested that the surface morphology structure of films is formed by rod-shaped aggregates produced by a two-step growth process: nucleation and diffusion-limited growth.