High-purity core / shell structured nanoparticles synthesis using high-frequency plasma technology and atomic layer deposition

Abstract In this study, an equipment for synthesizing high purity core/shell nanoparticles was developed using high frequency plasma technology and atomic layer deposition method. The plasma chamber was designed so that the gas phase precursor could stabilize the flow in the plasma, and a holder capable of adjusting the rotation and the height of substrate was constructed to enable the uniform deposition of nanoparticle on the substrate surface regardless of the precursor species. ALD (atomic layer deposition) deposition technique was used for the shell coating of the deposited nanoparticles. MTL (main transfer line) equipment was constructed to move the substrate from the plasma chamber to the ALD chamber without external exposure. By constructing a pneumatic gate, the contamination of ALD chamber by the plasma process can be prevented and the vacuum state can be maintained. By means of the SEM and TEM analysis, the growth rate of the core-TiO2 thin film and the growth thickness of the shell-Al2O3 were controlled at a growth rate of 0.05 μm/s and 1 Ẳ/cycle, respectively. In addition, it was confirmed that the weight fraction and the particle size can be controlled through the X-ray diffraction analysis and the dynamic light scattering analysis.