Sijoon Kim

Sijoon Kim is currently a postdoctoral researcher in the Department of Materials Science and Engineering at the University of Texas at Dallas (UTD) under the direction of Professor Jiyoung Kim. He received his B.S, M.S, and Ph. D degrees in School of Electrical and Electronic Engineering from Yonsei University, Seoul, Korea under the supervision of Professor Hyun Jae Kim, in 2008, 2010, and 2014, respectively. During his Ph. D. research, he studied on the development of the novel label-free DNA detection system using solution-processed oxide thin-film transistors. Then, he worked at Samsung Display Co., Ltd. as a Senior Engineer. In the May of 2016, he joined the group of Professor Jiyoung Kim at UTD. Up to now, his research has yielded 37 journal publications (12 papers as a first author) and he has participated in 35 international scientific and engineering conferences. A detailed list of publications can be found in google scholar: [Link to Google Scholar]

Currently, he is studying on the ferroelectricity in atomic layer deposited doped-hafnium oxide films for use in memory applications supported by Texas Instruments Incorporated. If the films had good ferroelectric memory characteristics, they would potentially allow current dynamic random-access memory (DRAM) process to create ferroelectric random-access memory (FRAM) using only a relatively small change in the materials/process. The goal of this project is to try to understand what impacts the saturation voltage and hopefully reduce this voltage. Before starting this research program, the biggest problem with the doped-hafnium oxide ferroelectric memory characteristics was a very high saturation voltage and a corresponding small # of endurance cycles before breakdown. In the first year, the research efforts has succeeded in achieving much lower ferroelectric saturation voltage as well as a corresponding increase in # of endurance cycles.

To progress of this project, he uses the electrical measurement tools: semiconductor parameter analyzer (Keithley 4200-SCS) for polarization-electric field (P-E) hysteresis and cycling endurance (positive-up-negative-down (PUND)) tests, Agilent 4284A for capacitance-voltage (C-V) hysteresis, and pulse generator (Agilent 81110A) for standard pulse-switching tests. The representative results of MIM capacitors with doped-hafnium oxide films measured by these tools are shown in the Figure.