Soft UV Nanoimprint Lithography and Its Applications

Abstract

Additional information is available at the end of the chapter http://dx.doi.org/10.5772/56186 . IntroductionLarμe-area nanopatterninμ tecνnoloμy νas demonstrated νiμν potential wνicν can siμniλi-cantly enνance tνe perλormance oλ many devices and products, sucν as LEDs, solar cells, νard disk drives, laser diodes, display, etc [ ]. For example, nano-patterned sappνire substrates NPSS and pνotonic crystals PνC νave been considered as tνe most eλλective approacνes to improve tνe liμνt output eλλiciency internal quantum eλλiciency and external quantum eλλiciency oλ LEDs and beam sνapinμ [ , ]. Tνe solar cells witν sub-micro anti-reλlective coatinμ exνibited νiμνer pνotocurrent and νiμνer power conversion eλλiciency compared to tνose witνout nanostructures [ ]. Moreover, tνe ability to produce larμe-area micro-and nanostructures on non-planar surλaces is oλ importance λor many applications sucν as optics, optoelectronics, nanopνotonics, imaμinμ tecνnoloμy, NEMS, and microλluidics [ ]. However, creatinμ larμe-area nanostructures on curved or non-planar surλaces are extremely diλλicult usinμ existinμ patterninμ approacνes. Furtνermore, a variety oλ existinμ nanopatterninμ tecνnoloμies sucν as electron beam litνoμrapνy EL" , optical litνoμrapνy, interλerence litνoμrapνy IL , etc., cannot cope witν all tνe practical demands oλ industrial applications witν respect to νiμν resolution, νiμν tνrouμνput, low cost, larμe area, and patterninμ on nonλlat and curved surλace. Tνereλore, new νiμν volume nanomanuλacturinμ tecνnoloμy stronμly needs to be exploited and developed so as to meet tνe tremendous requires oλ rapid μrowinμ markets.Nanoimprint litνoμrapνy NIL νas now been considered as a promisinμ nanopatterninμ metνod witν low cost, νiμν tνrouμνput and νiμν resolution, especially λor producinμ tνe larμe-area micro/nano scale patterns and complex -D structures and as well as νiμν-aspect-ratio λeatures. Due to tνese outstandinμ advantaμes, it was accepted by International Tecνnoloμy Roadmap λor Semiconductors ITRS in λor tνe and nm nodes, scνeduled λor industrial manuλacturinμ in . Tosνiba νas validated NIL λor nm and beyond. NIL νas also been listed as one oλ emerμinμ tecνnoloμies tνat will stronμly impact tνe world by Compared to otνer NIL processes tνermal NIL or νot embossinμ, UV-NIL witν riμid mold and nanopatterninμ metνods, soλt UV-NIL usinμ a λlexible or soλt mold νas been proven to be a very promisinμ approacν λor makinμ larμe-area patterns up to waλer-level in tνe micrometer and nanometer scale, λabricatinμ -D micro/nano structures and νiμν-aspect-ratio λeatures, especially producinμ larμe-area patterns on tνe non-planar surλaces even curved substrates at low-cost and witν νiμν tνrouμνput. Since tνe soλt mold stamp, template is adopted, tνe soλt UV-NIL process νas some unique advantaμes compared witν tνe traditional UV-NIL witν riμid mold. Tνese strenμtνs include Cost reduction. Cνeap soλt molds can be easily replicated λrom one expensive master, siμniλicantly reducinμ cost oλ tνe master template λabrication.Conλorma...

Flexible Organic Transistors with Controlled Nanomorphology

“…Nanogrooved polymer dielectrics were prepared by thermally assisted nanoimprint lithography (T-NIL). − Poly­(4-vinylphenol) cross-linked with 4,4′-(hexafluoroisopropylidene)­diphthalic anhydride (PVP:HDA, see Figure a for their molecular structures) was used as dielectric layers due to higher solvent resistance and low surface roughness. , As a master mold, nanogrooved SiO 2 (henceforth referred to as n-SiO 2 ) substrate was prepared by rubbing the n ++ Si/SiO 2 substrate with a diamond lapping disc with particle sizes of 100 nm as described in detail in the previous paper. ,, The photocross-linkable OrmoStamp was chosen as the stamping material because of its high hardness, which is required for achieving high-fidelity nanostructures on polymer substrates, and was cross-linked by ultraviolet light (wavelength ∼365 nm) in between the n-SiO 2 and ultrasmooth glass substrate. The resulting OrmoStamp substrate with nanobumps, a positive replica of the master mold (n-SiO 2 ), was placed onto spin-cast flat PVP:HDA (henceforth referred to as f-PVP) thin films under continuous heat and pressure to fabricate nanogrooved PVP:HDA (henceforth referred to as n-PVP).…”

“…11,12 As a master mold, nanogrooved SiO 2 (henceforth referred to as n-SiO 2 ) substrate was prepared by rubbing the n ++ Si/SiO 2 substrate with a diamond lapping disc with particle sizes of 100 nm as described in detail in the previous paper. 2,3,5 The photocrosslinkable OrmoStamp was chosen as the stamping material because of its high hardness, 13 which is required for achieving high-fidelity nanostructures on polymer substrates, and was flat PVP:HDA (henceforth referred to as f-PVP) thin films under continuous heat and pressure to fabricate nanogrooved PVP:HDA (henceforth referred to as n-PVP). All fabrication details can be found in the Supporting Information.…”

Ultrasound-assisted recovery of free-standing high-aspect-ratio micropillars

“…Young's modulus (10 MPa to 2 GPa). [23][24][25][26] According to the eqn (2), the critical aspect ratio for the uororesin micropillars can be up to 67.3 (10 MPa in Young's modulus), much larger than that of PDMS micropillars (which is 10, experimentally). In experiments, however, only few high-aspect-ratio uororesin micropillars can be alive, accompanying with amount of fractured micropillars in the silicon mold, which can be attributed to its high brittleness, as shown in Fig.…”

New Organic Photo-Curable Nanoimprint Resist ≪mr-NIL210≫ for High Volume Fabrication Applying Soft PDMS-Based Stamps

“…Due to the flexibility of the PDMS stamp imprint defects originating from particles on the substrate surfaces are much less critical as they can be easily overprinted in a way that the overall defectivity remains still low [7].…”