Taming the Electromagnetic Boundaries via Metasurfaces: From Theory and Fabrication to Functional Devices

Figure 20

Experimental demonstration of near-sighted silver lens. (a) Numerical simulation of intensity distribution of surface plasmons. (b) SEM image of resist pattern for (a). (c) Schematic diagram of the silver superlens experiment. (d) (Top) Focused-ion-beam image of the object with 40 nm line width, (middle) AFM images of topographic characterization in resist layer with a silver superlens, and (bottom) AFM images of topographic characterization in resist layer with the 35 nm thick superlens replaced by PMMA spacer as a control experiment. (e) Schematic of imaging lithography structure with a reflective Ag lens. (f) (Top) SEM image of the mask pattern “OPEN” characters, (bottom) SEM image of resist pattern. SEM image of half-pitch 32 nm dense lines resist pattern with plasmonic cavity lens. AFM image of half-pitch 22 nm resist pattern. Inset shows its two-dimensional (2D) Fourier analysis diagram. Figures are reproduced from (a, b) [31], (c, d) [30], and (e, f) [32].

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