Jaehyun Lee

 jaehyun.lee@kaist.ac.kr


 Education

  • 2017~     : Postdoctoral researcher, University of Glasgow, UK.
  • 2012~2016: KAIST Ph. D, EE
  • 2006~2008: Information and Communication University, MS, ECE
  • 2003~2006: Information and Communication University, BS, ECE
  • 2001~2003: Gwangju Science High School

Research


Topic: Schottky junction, SB-MOSFETs, Beyond MOSFETs

As gate length will be scaled down to under ~20nm, short channel effects have been significantly considered. In order to suppress short channel effects, body thickness (or junction depth) also will be scaled down to ~6nm. However, resistance in source/drain regions increases because of their thin body. Therefore, contact resistance reduction technology using Schottky junction is proposed.

A key for Schottky junction is Schottky barrier height (SBH). Generally, SBH is determined by Schottky-Mott rule. It predicts the SBH based on the work function of the metal relative to the electron affinity of the semiconductor. However, it was found experimentally that predicted SBH was wrong (Fermi-level pinning effect).

We have performed the first principle calculations (Density functional theory, DFT) to predict the SBH. For doing this job, optimized metal-semiconductor atom structures are necessary. With calculated SBH, we can investigate the performance of Schottky barrier (SB) MOSFETs.

Available DFT Tools: SIESTA, openMX



SB-MOSFETs are the most promising candidates as the future devices because of their low parasitic resistance and capacitance in source/drain region. However, low on-state current is major drawback due to their SBH. To enhance device performance in SB-MOSFETs, there are two ways: Reduction of SBH and improvement of carrier mobility.



Publications


  • Journal
  1. "Nonorthogonal sp3d5 Tight-Binding Parameterization of Single-Layer Phosphorene under Biaxial Strain and Application to FETs"  Jaehyun Lee, Junbeom Seo, Jung Hyun Oh, and Mincheol Shin, Nanotechnology, vol. 27, no. 24, 245202, May 2016.
  2.  "Density Functional Theory Based Simulation of Silicon Nanowire Field Effect Transistors," Mincheol Shin, Woo Jin Jeong, and Jaehyun Lee, J. of Applied Physics, Journal of Applied Physics, vol. 119, no. 15, p. 154505, Apr. 2016.
  3. "Performance Assessment of III-V Channel Ultra-thin-body Schottky-Barrier MOSFETs", Jaehyun Lee,Mincheol Shin, IEEE Electron Device Letters, Vol 35, pp. 726, July 2014.
  4. "P-type Nanowire Schottky Barrier MOSFETs: Comparative Study of Ge and Si Channel Devices", Wonchul Choi, Jaehyun Lee, and Mincheol Shin, IEEE Transactions on Electron Devices, Vol 61, pp. 37, January 2014.
  5. "Simulation Study of Germanium p-type Nanowire Schottky Barrier MosFETs", Jaehyun Lee andMincheol Shin, IEEE Electron Device Letters, Vol. 34, No 3, pp. 342-344, March, 2013 .
  6. ."Effects of pH and Ion Concentration in Phosphate Buffer Solution on the Sensitivity of the Silicon Nanowire BioFETs", Jaehyun Lee, Mincheol Shin, Chang-Guen Ahn, Chil Seong Ah, Chan Woo Park and Gun Yong Sung, J. of Korean Physical Society, Vol. 55, pp. 1621-1625, 2009.
  7. "Simulation Study of the Scaling Behavior of Top-Gated Carbon Nanotube Field Effect Transistors,"Mincheol Shin, Jaehyun Lee, and Chiyui Ahn, J. of Nanoscience and Nanotechnology, Vol. 8, No. 10, pp. 5389–5392, 2008.


  • Selected Conference
  1. "Device simulation based on DFT-NEGF using equivalent transport model", Woo Jin Jeong, Jaehyun Lee, Seungchul Kim, Kwang-Ryeol Lee, and Mincheol Shin, ICCP-9, Singapore, 2015.
  2. "Quantum Simulation of Si, GaAs, GaSb, and Ge Channel Ultra-Thin-Body Double-gate Negative Capacitance FETs", Jaehyun Lee, Woo Jin Jeong, Doo Hyung Kang, and Mincheol Shin, SNW, Hawaii, USA, 2014.
  3. "Dual-Material Gate Schottky Barrier UTB DG MOSFETs with Ge and III-V Channel", Wonchul choi, Jaehyun Lee, and Mincheol Shin, SNW, Hawaii, USA, 2014.
  4. "Quantum Simulation of III-V Double Gate Schottky Barrier MOSFETs", Jaehyun Lee, Yo Lum Lee, Ho Won Choi, and Mincheol Shin, IWCE-16, Nara, Japan, 2013.