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Titanium tetrachloride (TiCl4) is a well-known source of titanium (Ti) for the formation of titanium nitride (TiN) barrier material in the semiconductor interconnection process; however, the reaction of by-products with airborne molecules can cause unexpected pump trips and equipment breakdown from the by-product powder build-up. Plasma scrubbers are used to decompose by-products, but hydrogen chloride (HCl) and nitrogen oxides are produced during and after the process. The process mechanisms change when the temperature and applied power of the heat source change. In this paper, we study the influence of the reactor temperature and applied power to the heat source on the decomposition capacity of TiCl4 in a plasma pretreatment system (PPS). We examine the effect of the temperature and heat source power to understand the reaction mechanisms for the composition and decomposition of gaseous species with chemical reactions through simultaneous methods. We analyzed the system with computational fluid dynamics (CFD) and chemical kinetic simulation to investigate the changes of the system mechanism. Subsequently, we achieved results for the correlation between the temperature of the reactor, power applied to the heat source, composition and decomposition of species, and chemical reaction mechanisms. [ABSTRACT FROM AUTHOR]

One of the early design decisions for DC‐DC converters is the choice of an appropriate magnetic core material. Powder cores in particular are suitable due to their saturation flux density of up to 1.5 T. However, high DC currents constitutes a significant problem since the winding cross‐section rises with the current, which consequently increases AC losses due to skin effects. Another challenge is the reduction of winding layers to decrease proximity losses. This paper presents an improved single‐layer winding design procedure for DC‐DC converter powder cores. The procedure determines the optimum number of parallel cores and stacks. This way, the procedure enables a predefined maximum wire cross‐section for copper loss optimisation and single‐layer winding. The introduced approach defines the optimum switching frequency as a trade‐off between core loss and core volume. Finally, experimental tests with two setups validate 27 kW DC‐DC converters and hence the design procedure using Si‐IGBTs and SiC‐MOSFETs. The results demonstrate that SiC‐MOSFETs reduce core volume by a factor of 3 compared to Si‐IGBTs. Further, the SiC setup reaches high efficiencies of up to 98.53% compared to 98.17% for the Si‐based converter. [ABSTRACT FROM AUTHOR]

Abstract One of the early design decisions for DC‐DC converters is the choice of an appropriate magnetic core material. Powder cores in particular are suitable due to their saturation flux density of up to 1.5 T. However, high DC currents constitutes a significant problem since the winding cross‐section rises with the current, which consequently increases AC losses due to skin effects. Another challenge is the reduction of winding layers to decrease proximity losses. This paper presents an improved single‐layer winding design procedure for DC‐DC converter powder cores. The procedure determines the optimum number of parallel cores and stacks. This way, the procedure enables a predefined maximum wire cross‐section for copper loss optimisation and single‐layer winding. The introduced approach defines the optimum switching frequency as a trade‐off between core loss and core volume. Finally, experimental tests with two setups validate 27 kW DC‐DC converters and hence the design procedure using Si‐IGBTs and SiC‐MOSFETs. The results demonstrate that SiC‐MOSFETs reduce core volume by a factor of 3 compared to Si‐IGBTs. Further, the SiC setup reaches high efficiencies of up to 98.53% compared to 98.17% for the Si‐based converter.

In this study, the origin of growth pits on the surface of 4H-silicon carbide epitaxial films grown using a chemical vapor deposition reactor was clarified by evaluating the surface morphology of substrates immediately before the epitaxial growth and of epitaxial films. When the film was grown under non-optimized conditions, we found that numerous Si particles were formed on the surface of the substrate before the epitaxial growth and that the numerous growth pits on the subsequently grown epitaxial film were originated from Si particles. We observed that, by increasing the HCl flow rate through the outer nozzles in the gas inlet, which has a double-pipe structure consisting of inner and outer nozzles, the growth pit density was successfully decreased. [ABSTRACT FROM AUTHOR]

The operating temperature of integrated magnetic components can be critical. Excessively high temperature can significantly modify the properties of components, especially those of magnetic material, such as saturation magnetization and magnetic permeability. This article introduces an experimental characterization method using two different sensors. We compare the results obtained from these sensors. Initially, the method is validated using a "meander component, and subsequently, it is applied to planar spiral inductors, both with and without magnetic material. [ABSTRACT FROM AUTHOR]