Influence of Processing Factors on the Surface Properties of Zirconia Coatings Fabricated by Room Temperature Spray Process

Highly roughened surfaces on dental implants enhance the bone-bonding ability and in vivo cell adhesion on the implant surface. In this study, zirconia substrates were coated by powder coating using room temperature spray processing to improve their surface properties. Processing factors (particle size of the starting powder, number of repetitions of the deposition cycle, and spraying distance) were controlled to form a dense coating layer with high surface roughness on the zirconia substrate. Starting zirconia powders for coating were heat-treated at high temperature to control the particle size and kinetic energy. The coating layer fabricated from starting powder with a particle size of about 1.52 μm shows a homogeneous and dense microstructure, and it has a maximum surface roughness about 0.37 μm. The surface roughness of the film coatings increased with the number of times that the deposition cycle was repeated. No phase changes between the starting powder and the coating layer were observed, and all of the materials show identical tetragonal phases.

Overall reaction mechanism for a full atomic layer deposition cycle of W films on TiN surfaces: first-principles study

We investigated the overall ALD reaction mechanism for W deposition on TiN surfaces based on DFT calculation as well as the detailed dissociative reactions of WF6.

Kinetics Study of Aluminum Deposition on Inner Wall of Pipes by Atomic Layer Deposition

In this paper, feasibility of aluminium deposition on inner wall of pipes by atomic layer deposition was studied. Firstly, by solving kinetics equation of gas adsorption on the pipe inner wall, the time for the reactant to reach saturated adsorption on the wall was calculated. Secondly, according to the aluminium crystal structure, the thickness of each deposition cycle was obtained. Finally, the minimum aluminium thickness and number of atomic layer deposition cycles that can meet electromagnetic requirement of wave guide was calculated.

Thin HfO2 Films Deposited via Alternating Pulses of Hf(NO3)4 and HfCl4

A novel technique for deposition of metal oxide films is demonstrated in which alternating pulses of metal-nitrate and metal-chloride precursors are used. The metal nitrate, Hf(NO3)4, acts as the oxidizing agent, avoiding the use of a separate oxidizing species such as H2O. This method results in greater than one monolayer per cycle deposition rate of HfO2 films compared to the use of a single precursor and enables deposition directly on H-terminated Si due to the reactivity of Hf(NO3)4. It was found that performing a short in-situ anneal after every deposition cycle increases film density and improves electrical characteristics. Films are characterized via capacitance vs. voltage, current vs. voltage, spectroscopic ellipsometry, and x-ray diffraction and reflectivity.

Self-control Phenomenon for Crystallinity and Morphology Observed at Epitaxial Growth of BaTiO3 by Alternating Deposition Method

ABSTRACTWe directly observed self-control crystallization of epitaxial BaTiO3 films during alternate depositions of BaO and TiO2. When TiO2 (or BaO) was supplied excessively, surface crystallinity and smoothness degraded due to three-dimensional (3D) growth. However, when the following BaO (or TiO2) was supplied onto the rough TiO2 (or BaO) surface, the surface smoothness was recovered drastically. It was found that a single phase BaTiO3 film grew by repeating the alternate deposition cycle of excessive supply of both BaO and TiO2. The mechanism of this phenomenon was discussed.