- 1990 Columbia University (Ph.D – Electrical Engineering)
- 1982 KAIST (M.S. – Electrical Engineering)
- 1980 Seoul National University (B.S. – Electronics Engineering)
- 1994 – Present GIST, Professor
- 1990 -1994 Bell Communications Research (Bellcore), Postdoctoral MTS
- 1986 -1990 NSF Center for Telecommunications Research (CTR), Graduate research assistant
- 1986 -1990 Electronics and Telecommunications Research Institute, Senior MTS
- Compound semiconductor epitaxy
- Ultra-high-speed electronic devices (HEMTs and HBTs)
- O/E and E/O devices for optical communications
- Monolithic microwave and millimeter-wave circuits for wireless communications
- Photonic microwave devices and subsystems for universal communication systems
- High-Speed Integrated Circuit LaboratoryPrimary research objectives of this laboratory include design, fabrication, characterization of high-speed devices, integrated circuits, and subsystems for high-speed optical and wireless communication system applications. The laboratory has design tools including a Silvaco device simulator, microwave circuit design simulators including HP Microwave Design Software (MDS/ADS) and HSPICE, and HP ICCAP for device parameter extraction and modeling. The laboratory also has a clean room that is equipped with various compound semiconductor device and circuit fabrication equipments and facilities. The laboratory currently has characterization equipments including a semiconductor parameter analyzer, a spectrum anayzers (50 GHz), a vector network analyzer (50 GHz), a load-pull power measurement system (50 GHz), a high-frequency noise measurement system (40 GHz), a low-frequency noise measurement system (1 Hz – 1 MHz), a microwave probe station, a communication signal analyzer (optical: 40 Gbps, electrical: 50 GHz), a subpicosecond optical sampling system, a low-noise amplifier, and a low temperature probe station. These measurement systems primary cover a frequency range up to 50 GHz and will be upgraded to cover higher frequency ranges.On-going research projects in the laboratory are the development of millimeter-wave device including InPand GaAs-based HEMT, HBT, compound seniconductor MOSFETs, high-speed photodetectors, quantum well/dot far-infrared photodetectors and the development of MMICs, modules for wireless communications, modules for millimeterwave-over-fiber (MMoF) sysetm. Detailed research topics include epitaxial growth using CBEand MBE, device fabrication, device modelling and parameter extraction, microwave device (noise and power) characterization, high-speed optical device characterization, MMIC design, MMIC fabrication, reliability of devices and MMICs.
Semiconductor Processing Laboratory (Clean Room)
There is a clean room (4,320 square-feet with the class of 1,000 to 10,000) that is equipped with facilities for fabrication of compound semiconductor devices and circuits for high-speed communication applications. The fabrication equipments currently installed are a V80H chemical beam epitaxy system (CBE), a V80H-10K Molecular Beam Epitaxy(MBE), a J5800LV scanning electron microscope (SEM), a Raith Elphy Plus SEM-based e-beam lithography system, a Karl Suss Jirset Photoresist spin coater, a Karl Suss MJB3 mask aligner with a backside alignment capability, Leicaoptical microscopes, an Oxford Plus80 reactive ion etching (RIE) system, an Oxford Plus80 plasma enhance chemical vapor deposition (PECVD) system, a Temescal BJD-1800 e-beam evaporator system, an Alpha-step profiler, and and an electro-chemical CV profiler (Polaron), chemical wet stations. The equipments are capable of fabricating ultra-high-speed devices including high-electron mobility transistors (HEMTs), heterojunction bipolar transistors (HBTs), high-speed detectors, and modulators operating up to a few hundred GHz and integrated circuits operating up to tens of GHz.