YoungChol Byun

YoungChol Byun [Link to linkedin] is currently a postdoctoral researcher in the department of materials science and engineering at the University of Texas at Dallas under the direction of Prof. Jiyoung Kim. He completed his B.S., M.S., and Ph.D. in materials science and engineering from the Sungkyunkwan University in Suwon, Korea under the supervision of Prof. Hyoungsub Kim. During his Ph.D., he focuses on the Electrical and physical characteristics of atomic layer deposited high-k gate dielectrics on InP, GaAs and InGaAs for next generation CMOS devices. His current research is focused on the development and characterizations of GaN HEMTs, InGaAs MOSFETs and SiNx films using ALD with various industrial collaborators. Also, he has 22 publications in peer-reviewed journals (# 7 first and corresponding author), 30 presentations in conferences. A detailed list of publications can be found in google scholar: [Link to Google Scholar]

His main research project is the development of epitaxial structure design and epitaxial growth system for high-voltage power semiconductors program supported by the IT R&D program of MOTIE (the Ministry of Trade, Industry, and Energy) / KEIT (Korea Evaluation Institute of Technology) with TES and University of Houston. The goal of this global R&D project is to design and develop new concept epitaxial growth systems and material structures for next-generation high-power switching and RF devices based on GaN on Si technology. In UTD, a specific theme is the surface treatment and device characterization of MOCVD GaN HEMTs. In the first and second year, his team successfully developed the low-temperature gate oxide for GaN on Si HEMTs which shows superior electrical characteristics.

His main tool is the Atomic Layer Deposition. Atomic layer deposition (ALD) is a precise deposition technique which has unique advantages compared to conventional chemical vapor deposition (CVD) such as film uniformity, reproducibility, less contamination in films and easy control of the chemical composition. ALD technology is based on the chemical adsorption of precursors on surfaces to deposit the nano-scale thin films. Each precursor is separately injected into the chamber and chemically adsorbed to the sample surface. Also, ALD uses sequential, self-limiting and surface controlled gas phase chemical reactions to achieve precise control of film growth in nanometer thickness regime. Precursors will not react until contact with the surface which means the film growth proceeds by repeated atomic layers deposition from the surface. As a result of the film formation mechanism, ALD films are dense, defect and pinhole-free and its thickness can be precisely controlled on atomic scale. In. Dr. Kim’s lab, there is a thermal atomic layer deposition system (Saavannah S100, Ultratech/Cambridge nanotech, USA). This system has 4 inch wafer capability, 325 °C maximum substrate temperature, a four precursor manifold with selectable ozone/water oxidant and flexible control software enabling customizable process flow. In ALD system during thin film deposition, nitrogen carrier gas are continuously flowing while pulsing and purging a precursor. For heating chamber, there are two heaters, Tubular heater and inner disk heater at outside and inside, respectively. Both heater temperatures are controlled by resistance temperature detector. Chamber pumping is done by mechanical pump which are acted by fomblin oil.