1 . T itle : Partial Crystallization of HfO2 and Its Application to Nanoscale Devic es

1. SEMINAR 1. Title : Partial Crystallization of HfO2 and Its Application toNanoscale Devices 2. Speaker : Professor Won Jong Yoo (Sungkyunkwan University) 3. Time : 16:00 – 17:30, Tuesday, 30 May, 2006 4. Place : e+ Lecture Hall (room 83188), 2nd Research Building, Sungkyunkwan University 5. Summary : The demands for non-volatile memories (NVM) in recent years have increased rapidlydue to the growth of mobile device industries. Silicon-Oxide-Nitride-Oxide-Silicon (SONOS) type flash memory layer is extensively studiedbecause of its potential as a high density memory. The high-k dielectric material HfO2 is considered as a better trapping layer material than Si3N4 in SONOS because high k can provide better vertical scalability anddata retention property. Amorphous HfO2 crystallizes during high-temperature (>650C) treatments, which is known as a drawback of HfO2 since the crystallization of dielectric layer can induce high leakage current. According to the crystallization result obtained by x-ray diffraction, high intensity peaks of (-111) and (111) are observed after the thermal treatment for 5 s in the temperature range of 800C - 1000C. However, AFM topography image clearly shows that the crystallization across the HfO2 film is non-uniform and the grains in the film are formed via partial crystallization. We consider that these grains act similarly to nanocrystal dots, which effectively suppress lateral charge migration, via charge localization inside the grains or at the grain boundaries. Excellent high density memory properties are achieved by channel hot electron injection programming and outstanding charge retention property is achieved in both room temperature and at 85C. The novel way of mimicking nanocrystal structure with partially crystallized continuous HfO2 trapping layer easily enables multi-bit/cell operation and greatly extends the storage capacity of SONOS type flash memory. 6 Background of Speaker: Education 1982 Metallurgical Engineering, Seoul National University, B.S 1984 Metallurgical Engineering, Seoul National University, M.S 1993 Materials Engineering, Rensselaer Polytechnic Institute, Ph.D Work Experience 1984-1987 Researcher, Research Institute of Science and Technology, Korea 1987-1989 Researcher IBM T.J. Watson Research Center, USA 1993-1999 Principal Researcher, Samsung Electronics, Korea 1999-2006 Associate Professor, National University of Singapore 2006- Professor, Mechanical Engineering, Sungkyunkwan University SKKU Advanced Institute of Nano Technology (SAINT) 7. Questions : Professor Won Jong Yoo (☏ 031-290-7468) Sungkyunkwan University