Tien-Chien Jen is a Professor in the Department of Mechanical Engineering Science in the School of Mechanical and Industrial Engineering at the University of Johannesburg in South Africa. His current interest centers on cutting-edge hydrogen energy generation and storage and advanced materials processing and manufacturing. Topics range from constructing a hydrogen-powered ATV to finding novel materials and techniques to coat fuel cells to increase electron conversion efficiency, and traditional and non-traditional manufacturing processes development.Professor Jen has written a total of 173 peer-reviewed papers including 80 peer-reviewed journal papers, published in many prestigious journals includingInternational Journal of Heat and Mass Transfer, ASME Journal of Heat Transfer, ASME Journal of Mechanical DesignandASME Journal of Manufacturing Science and Engineering. He also has written five chapter papers (shown below) including a chapter inNumerical Simulation Proton Exchange Membrane Fuel Cell,published by WIT Press, and another chapter inApplication of Lattice Boltzmann Method in Fluid Flow and Heat Transfer in Computational Fluid Dynamics – Technology and Application, and more.
In 2010, he has been elected to the status of Fellow of American Society of Mechanical Engineer (ASME) in recognizing his significant contributions in the areas of thermal science and manufacturing.
Atomic layer deposition (ALD) is an excellent deposition technique based on self-limiting surface chemical reactions to coat substrates with highly uniform and conformal thin films under precise thickness controls in atomic scales. ALD is derived from chemical vapor deposition (CVD) where in an ALD each gaseous precursor is alternately pulsed into the reactor; and a binary reaction is split into self-limiting surface reactions between the two gaseous precursorsaandb, and the absorbed species on the substrate. Also, to avoid non-uniformity in film depositions due to interactions and gas-phase reactions between the precursors, the reactor is purged by an inert gas between precursor exposures.
This presentation illustrates the current research progress performed in Professor Jen’s research group. The transient multi-wafer batch ALD process of depositing Al2O3films on silicon wafers using trimethylaluminum (TMA) and water is studied by both experimental and numerical approaches. To find the influence of wafer layout on the deposition process, two types of wafer arrangements, i.e., vertical and horizontal multi-wafer ALD, are specifically investigated. In particular, the two arrangements are compared in terms of alumina thin film growth rate. Further investigation on the detailed knowledge of the precursor transient pulsing process is carried out by 3D numerical simulations.
