Electron beam lithography transfer

The LB film depositions were performed using a Joyce-Loebl Langmuir Trough IV equipped with a microbalance for measurement of the surface pressure by the Wilhelmy plate method. Filtered deionized water with a pH of 7 was used for the subphase. For the electron beam lithography study, PMMA was spread on the water surface from a dilute benzene solution ( 10 mg PMMA in 20 ml benzene). The novolac/PAC mixtures were spread from solutions ( 20 mg solids in 10 ml solvent) of isopropyl acetate. For the fluorescence studies, the PMMA/PDA mixture was spread on fee water surface from a dilute benzene solution (1.75 mg PDA and 8.33 mg PMMA in 20 ml benzene). Prior to compression, a 20 min interval was allowed for solvent evaporation. The Langmuir film was compressed to the desired transfer pressure at a rate of 50 cm2/min, followed by a 20 minute equilibration period. The Cr-coated silicon wafers and quartz wafers were immersed into fee subphase before... 

Ferromagnetic rings are also fabricated by using electron-beam lithography with a lift-off process for pattern transfer [76]. These nanoscale ferromagnetic rings have a smallest outer diameter of 90 nm, inner diameter of 30 nm and thickness of 10 nm. 

Dip-pen lithography, SAM, hot embossing, nanoimprint lithography, electron beam lithography, dry etching, and reactive ion etching are techniques that can be used to prepare nanostructures with 50-70 nm dimensions. Nanomechanical techniques include processes that involve local transfer of material from a tool onto a substrate when either the tool or the substrate is prestructured. 

More details on fused silica mold fabrication can be found elsewhere [80]. In general, a resist is patterned using electron-beam lithography and then transferred to a thin (between 8 and 20 nm) chromium layer with a CI2/O2 plasma. Afterwards, fused silica is etched in a fluorocarbon plasma using the chromium layer as a hard mask. Finally, this hard mask is removed in a wet or dry process. 

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