报告题目：Nanofabrication and Surface Nanopatterning with Focused Ion Beam
报告人： Dr. Wei ZHOU，School of Mechanical & Aerospace
Engineering, Nanyang Technological University
时间： 2013年6月24日下午3：00—
地点： 曹光彪大楼326室
邀请人：洪樟连教授
周伟教授简介：
Dr Wei Zhou is Associate Professor (tenured) of Nanyang Technological University (NTU). He has recently been elected a Visiting Fellow of Churchill College, Cambridge University. His major research interest lies in materials processing (especially welding) & nanofabrication using energetic beams (FIB), including focused ion beam and laser beam. He obtained BEng from Tsinghua University in 1985 and PhD form Cambridge University in 1991. In 2002 he worked in Harvard University as a Visiting Scholar in Applied Physics carrying out researches on FIB-induced self-organization of nanostructures. He was Director of Precision Engineering and Nanotechnology Centre, NTU and Vice President of Singapore Welding Society (SWS). He is Chairman of Welding Technology Committee of SWS, Chairman of National Committee on ISO/TC 44 “Welding and Allied Processes”, and recipient of Merit Award from SPRING in recognition of his “invaluable contributions towards quality and standards in Singapore”. In Feb 2011 he was granted United States Patent 7888663 for invention of a nano-lens. He has supervised 10 PhD students and published 140 SCI-indexed journal papers. One of his papers has been cited more than 300 times.
Presentation title: Nanofabrication and Surface Nanopatterning with Focused Ion Beam
Abstract：Nanoscale structures have many applications. We demonstrate the successful use of 30-50 keV Ga+ Focused Ion Beam (FIB) as a one-step maskless and resistless nanofabrication tool for making nanoscale periodic pillars, wells, and gratings. However, the “direct writing” fabrication process may be severely affected by ion-induced self-organization of surface patterns. We studied a wide range of materials (including pure metals, semiconductor elements and compounds) and identified the major causes for the spontaneous formation of surface patterns, including anisotropic surface diffusion (in Sn and Ti), ion-induced nano-explosion (in Ge and GaSb), and severe Ga redeposition (in GaAs, GaSb and GaN). On the one hand, we explored various ways to suppress the spontaneous surface patterns when they are undesirable. On the other hand, we managed to make use of the phenomena to produce self-organized ripples, nano-dots or nano-rods. We succeeded in putting forward phenomenogical model describing mechanisms of self-organization for some of the nanostructures through monitoring evolution of the surface patterns using in-situ real-time secondary ion and secondary electron imaging. Finally, examples are given on use of the nanostructures for site-specific microscopic analyses of materials and for making a novel plasmonic nano-lens.
浙江大学材料系无机非金属材料研究所
硅材料国家重点实验室
欢迎师生参加！2013年6月18日
