Ag tip-insulator-metal structure with bottom-up light illumination is proposed and theoretically analyzed. It shows that there is a strong plasmonic coupling between Ag tip and metallic surface. Different from oblique light illumination, this novel design possesses unique advantages of symmetrical hot spot profile and enlarged depth of focus at a sub-10-nm spatial resolution. Influences of tip size, insulator, and metallic layer thickness are studied. It is found that the metallic layer thickness greatly affects the plasmonic hot spot quality. Meanwhile, the thickness of photoresist plays a major role in controlling light spot size, indicating that much higher resolution can be achieved for the Ag tips with large curvature radius.
Chinese Acad Sci, Inst Opt & Elect, State Key Lab Opt Technol Nanofabricat & Microeng, Chengdu 610209, Peoples R China
Zhou, Jie,Wang, Changtao,Zhao, Zeyu,et al. Design and Theoretical Analyses of Tip-Insulator-Metal Structure with Bottom-Up Light Illumination: Formations of Elongated Symmetrical Plasmonic Hot Spot at Sub-10 nm Resolution[J]. PLASMONICS,2013,8(2):1073-1078.