Fig. 6
From: Highly sensitive ultrasound detection using nanofabricated polymer micro-ring resonators
(Reproduced with permission from [60])
Nanofabrication of polymer MRRs by NIL. a A schematic illustration of fabrication procedures of NIL. b and c Top view and cross-sectional view of SEM images for fabrication results of the PS MRR by NIL with the engraved SiO2 pattern on Si mold. Scale bar: b 20 μm, c 2 μm. Reproduced with permission from [51]. SEM images of PS MRR sidewalls by NIL using the Si mold fabricated by EBL and RIE processes: d without PMMA resist reflow process, e with PMMA resist reflow process, and f with PMMA resist reflow and thermal oxidation process. Scale bar: d, e, f 500 nm, Reproduced with permission from [28]. g A SEM image of PS MRR with a diameter of 60 μm fabricated by NIL with the Si mold. Scale bar: 30 μm. h A cross-sectional SEM image of the waveguide with a width of 1 μm and a height of 1.4 μm. Scale bar: 2 μm