UN CO RR EC TE D PR OO F 1 Development of an electrodeposited nanomold from compositionally modulated alloys

10 Abstract 11 Electrodeposited multilayers of NiCu/Cu and NiFeCu/Cu were examined for nanoimprinting applications. Layer 12 sizes on the order of 100 nm were deposited and the copper layer etched. Current efficiency and layer composition of 13 electrolytes having different pH values were examined utilizing a rotating disk electrode. Due to large grain growth 14 in the NiCu/Cu system, the bilayers resulted in a macroscopic waviness of the layers. Adding Fe in a small 15 concentration successfully produced straight layers. As an example of the replication technique, the metal 16 multilayer-etched stamp was used to cast the multilayer image in rubber and emboss it in Teflon â. 19 The development of an electrodeposited nanomold is of 20 interest in optics and electronics industries for nanoim-21 printing applications [1–3]. For example, sub-wave-22 length optics requires lithographic patterning of widths 23 from 50 to 200 nm, where the percentage of stripe width 24 to stripe spacing (duty factor) determines the effective 25 refractive index, and the height of the grating determines 26 the phase retardation. The degree of precision needed is 27 comparable with that achievable by high performance 28 vapor or e-beam deposition systems. The electrodepos-29 ition method presented here is a proposed alternative 30 method of producing a master stamper that is less costly 31 and capable of achieving nanometer accuracy and 32 resolution. 33 Figure 1 illustrates the fabrication of an extremely 34 precise electrodeposited nanostamp, and its applica-35 tion as a nanoimprint master stamper to duplicate the 36 image on a substance. The master stamp is fabricated 37 from the electrodeposition of a compositionally modu-38 lated multilayer, with alternating layers having disparate 39 nobilities. After electrodeposition, one layer is selec-40 tively etched away to create a relief structure. The 41 nanostamp is subsequently used as a master for casting 42 or embossing a polymeric, ceramic or soft metal 43 material. 44 Electrodeposition has been widely demonstrated as an 45 effective method to produce multilayers, for example for 46 giant magnetoresistance [4–19] and enhanced hardness 47 [20, 21]. Additionally, etching solutions have been used 48 to preferentially etch large, 100 nm layer sizes of 49 multilayers for scanning electron microscopy (SEM) 50 characterization [21–23]. On a micron scale, the selective 51 etching of layered materials has also been established for 52 lithographically fabricated MicroElectroMechanical 53 Systems [24, 25]. For example, Leith and Schwartz [26] 54 selectively etched an iron-rich …