DOCSLIB.ORG

Soft Lithography for Micro- and Nanoscale Patterning Dong Qin1, Younan Xia2 & George M Whitesides3

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Soft Lithography for Micro- and Nanoscale Patterning Dong Qin1, Younan Xia2 & George M Whitesides3 PROTOCOL Soft lithography for micro- and nanoscale patterning Dong Qin1, Younan Xia2 & George M Whitesides3 1Nano Research Facility and Department of Energy, Environmental, and Chemical Engineering and 2Department of Biomedical Engineering, Washington University, St. Louis, Missouri, USA. 3Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, USA. Correspondence should be addressed to G.M.W. ([email protected]). Published online 18 February 2010; doi:10.1038/nprot.2009.234 This protocol provides an introduction to soft lithography—a collection of techniques based on printing, molding and embossing with an elastomeric stamp. Soft lithography provides access to three-dimensional and curved structures, tolerates a wide variety of otocols materials, generates well-defined and controllable surface chemistries, and is generally compatible with biological applications. It is also low in cost, experimentally convenient and has emerged as a technology useful for a number of applications that include cell biology, microfluidics, lab-on-a-chip, microelectromechanical systems and flexible electronics/photonics. As examples, here naturepr / we focus on three of the commonly used soft lithographic techniques: (i) microcontact printing of alkanethiols and proteins on m o gold-coated and glass substrates; (ii) replica molding for fabrication of microfluidic devices in poly(dimethyl siloxane), and of c . e r nanostructures in polyurethane or epoxy; and (iii) solvent-assisted micromolding of nanostructures in poly(methyl methacrylate). u t a n . w w INTRODUCTION w / / : The strategy of ‘smaller brings new capability’ has begun to change with an elastomeric stamp (Protocols for µCP, REM and SAMIM p t 1 t the world of biotechnology as it has transformed microelectronics . are described in the Procedure and outlined in Fig. 1). New variants h Successful applications of small systems include microarrays for such as dip-pen nanolithography have also emerged19–21. All these p 2 u high-speed DNA sequencing , microfluidic devices for perform- techniques use organic and polymeric materials that are referred o r ing PCR3, lab-on-a-chip (LOC) systems for synthesis and analysis G to as soft matter by physicists. 4 g of peptide and oligonucleotide libraries , and microchips for drug n i 5 6 h screening and for investigation of cultured cells . As the workhorse µCP s i 7 l of microfabrication, photolithography has contributed an impor- As the forerunner of soft lithography, µCP provides an attractive b u tant role in most of these applications, including the fabrication route to microscale patterns and structures needed for applications P e of DNA arrays in the late 1980s (ref. 8). However, this technique in biotechnology. For example, µCP offers an ability to engineer r u t has a number of limitations for applications related to biological the properties of a surface with molecular-level detail using self- a N systems. First, photolithography is an intrinsically expensive process assembled monolayers (SAMs) of alkanethiols on a substrate coated 0 because the equipment used was developed for the highly demand- with a metal such as gold (Au), silver (Ag), copper (Cu), palladium 1 0 22 2 ing processes required for fabrication of microelectronic devices. (Pd) and platinum (Pt) . In this study, the substrate refers to a © The capital investment required to build a clean room makes physical object, which is somewhat different from the meaning in photolithography less than accessible to most chemists, biochem- enzymology. Typical planar substrates for forming alkanethiolate ists and biologists. Thus, photolithography is most successful when SAMs include thin films of a metal deposited on silicon, mica, glass applied to a limited set of materials. Users wishing to study ‘dirty’ or even plastic materials. The substrates can be easily prepared by organic systems are usually excluded from an electronics-qualified physical vapor deposition methods, such as thermal or electron clean-room facility. Second, photolithography is often carried out beam evaporation23. The patterned SAMs have proved valuable for by projecting a pattern on a photomask onto a photoresist film. studying the role of spatial signaling in cell biology by exquisitely Although photomasks are commercially available, the time and controlling the molecular structure of a surface in contact with cost involved in the fabrication of such masks present a signi- cells24. One can create well-defined regions with ‘cell-friendly’ (protein- ficant barrier to the use of photolithography in rapid, inexpensive covered) and ‘cell-unfriendly’ (polyethylene glycol–terminated) SAMs prototyping of test patterns and devices. Third, photolithography to pattern endothelial cells on a surface and then examine how the provides little or no control over surface chemistry, and it is not cells respond to lateral confinement, and to being released from applicable to curved or non-planar substrates. confinement24. Furthermore, µCP has been successfully used to print Soft lithography9 represents a conceptually different approach to precise patterns of axon guidance molecules, which can then serve rapid prototyping of various types of both microscale and nano- as templates for growing chick retinal ganglion cell axons25. scale structures, and devices on planar, curved, flexible and soft substrates especially when low cost is required. A large number REM of patterning techniques—microcontact printing (µCP)10, replica Alternatively, REM provides a new method for fabricating micro- molding (REM)11, microtransfer molding12, micromolding in fluidic devices using poly(dimethyl siloxane) (PDMS)26, and this capillary13, solvent-assisted micromolding (SAMIM)14, phase- method has proved to be particularly suitable for various bio- shifting edge lithography15, nanotransfer printing16, decal transfer medical applications27–32. Compared with the inorganic materials lithography17 and nanoskiving18—form the basis of soft lithogra- such as silicon and glass that are used in microelectronics and phy; they are essentially based on printing, molding and embossing optics, and which have been explored but largely discarded for NATURE PROTOCOLS | VOL.5 NO.3 | 2010 | 491 PROTOCOL biologically directed microfluidics, PDMS offers a number of I. Design of pattern (Steps 1 and 2) unique and attractive features. They are33: (i) It has a shear modulus of 0.25 MPa and a Young’s modulus of roughly 0.5 MPa (charac- Photomask teristic of a moderately stiff elastomer). This elastomeric character II. Fabrication of master Positive resist Negative resist allows it to conform to a surface and achieve atomic-level contact, a (Steps 3–6) feature that is useful in forming and in sealing microfluidic systems. Substrate Substrate (ii) It is non-toxic and readily available from commercial sources at acceptable prices (~$80/kg). (iii) It is optically transparent down III. Fabrication of PDMS stamp to about 300 nm. (iv) It is intrinsically hydrophobic (with a water (Steps 6–11 or 12–19) contact angle of ~110°), but its surface can be modified by brief PDMS PDMS exposure to an oxygen plasma to become hydrophilic (with a water contact angle around 10°). (v) It can adhere and seal reversibly or, 26,34 IV. Soft lithography after oxidation, irreversibly to many different types of substrates . (Steps 20–46) The ease of production associated with PDMS microfluidic struc- otocols Microcontact printing of SAM Microcontact printing of protein tures will become even greater as the focus of microfluidics shifts (Steps 20–25) (Steps 26–29) from demonstration of components and devices to development PDMS PDMS of fully functional systems31,35,36. naturepr / Silicon Glass m Soft lithography also provides a set of attractive tools for nano- o c . fabrication. ‘Nanofabrication’ refers to a process that makes func- e r tional structures with at least one lateral dimension smaller than Silicon Glass u t a 100 nm (ref. 37). REM and SAMIM are two techniques based on n . w molding or embossing with an elastomeric stamp. Both can pro- Replica molding of PU or epoxy Solvent-assisted micro-molding of PMMA w (Steps 37–41) (Steps 42–47) w duce nanoscale structures in various soft materials, in parallel, over / / : 2 PDMS PDMS p large areas (3 cm with 100-nm features), and at relatively low cost. t t h When combined with selective etching and lift-off, these nanostruc- Solvent p tures have been transferred into metals and then used as substrates PU or epoxy PMMA u Substrate o Substrate r for biosensing. The methods of detection have included optical G 38 39 diffraction , surface plasmon resonance , surface-enhanced g 40 41 n Raman scattering and electrochemistry . i Substrate Substrate h s i l Figure 1 | Schematic illustration of the four major steps involved in soft b Photolithography versus soft lithography u lithography and three major soft lithographic techniques. P Photolithography will continue as the dominant technology in fabri- e r cation of semiconductor devices and systems that have stringent u t printing, molding and embossing. The term soft lithography ‘refers a requirements on the alignment, continuity, isolation and uniform- N 9 ity in the final patterns. There are, however, many existing and to the fabrication of patterned copies using the PDMS stamp’ ; 0 1 emerging applications for soft lithography that take advantage of and the overall process—from pattern design to fabrication of 0 2 (or require) the characteristics of these
Load more

Recommended publications
  • Nanoimprint Lithography: Methods and Material Requirements**
    REVIEW DOI: 10.1002/adma.200600882 Nanoimprint Lithography: Methods and Material Requirements** By L. Jay Guo* Nanoimprint lithography (NIL) is a nonconventional lithographic technique for high-throughput patterning of polymer nanostructures at great precision and at low costs. Unlike traditional lithographic ap- proaches, which achieve pattern definition through the use of photons or electrons to modify the chemical and physical properties of the resist, NIL relies on direct mechanical deformation of the resist material and can therefore achieve resolutions beyond the limitations set by light diffraction or beam scattering that are encountered in conventional techniques. This Review covers the basic principles of nanoimprinting, with an emphasis on the requirements on materi- als for the imprinting mold, surface properties, and resist materials for successful and reliable nanostructure replication. 1. Introduction proaches towards nanostructure fabrication have been exploited in the past 15 years, without resorting to expensive The ability to fabricate structures from the micro- to the tools such as those used in deep-UV projection lithography nanoscale with high precision in a wide variety of materials is and electron-beam lithography. These techniques include [1] of crucial importance to the advancement of micro- and nano- microcontact printing (or soft lithography), nanoimprint [2] technology and the nanosciences. The semiconductor industry lithography (NIL), scanning-probe-based techniques (e.g., [3] has been pushing high-precision nanoscale lithography to atomic force microscope lithography), and dip-pen lithogra- [4] manufacture ever-smaller transistors and higher-density inte- phy. A good overview of several of these techniques was [5] grated circuits (ICs). Critical issues, such as resolution, relia- presented in a recent paper.
    [Show full text]
  • A Review of Current Methods in Microfluidic Device Fabrication And
    inventions Review A Review of Current Methods in Microfluidic Device Fabrication and Future Commercialization Prospects Bruce K. Gale * ID , Alexander R. Jafek ID , Christopher J. Lambert ID , Brady L. Goenner, Hossein Moghimifam, Ugochukwu C. Nze ID and Suraj Kumar Kamarapu ID Department of Mechanical Engineering, University of Utah, Salt Lake City, UT 84112, USA; [email protected] (A.R.J.); [email protected] (C.J.L.); [email protected] (B.L.G.); [email protected] (H.M.); [email protected] (U.C.N.); [email protected] (S.K.K.) * Correspondence: [email protected]; Tel.: +1-801-585-5944 Received: 30 June 2018; Accepted: 20 August 2018; Published: 28 August 2018 Abstract: Microfluidic devices currently play an important role in many biological, chemical, and engineering applications, and there are many ways to fabricate the necessary channel and feature dimensions. In this review, we provide an overview of microfabrication techniques that are relevant to both research and commercial use. A special emphasis on both the most practical and the recently developed methods for microfluidic device fabrication is applied, and it leads us to specifically address laminate, molding, 3D printing, and high resolution nanofabrication techniques. The methods are compared for their relative costs and benefits, with special attention paid to the commercialization prospects of the various technologies. Keywords: microfabrication; nanofabrication; microfluidics; nanofluidics; 3D printing; laminates; molding 1. Introduction Microfluidics is a growing field of research which pertains to the manipulation of fluids on the microscale level, and it is identified most commonly by devices with critical dimensions of less than 1 mm.
    [Show full text]
  • Electron Beam Lithography for Nanofabrication
    Departament de Física, Facultat de Ciències Universitat Autònoma de Barcelona January 2008 ElectronElectron beambeam lithographylithography forfor NanofabricationNanofabrication PhD Thesis by Gemma Rius Suñé Directed by Francesc Pérez-Murano and Joan Bausells Institut de Microelectrònica de Barcelona -------------------------------------------- The cover image corresponds to a PMMA residual found after the stripping of the resist layer. Even though it seems a new planet, it is 1µm in diameter. -------------------------------------------- This memory reflects part of the work performed at the Nanofabrication Laboratory of the IMB–CNM during the past 5 years, based on Electron Beam Lithography (EBL). Nanofabrication is a very active area of research, as can be noticed from the number of publications that appear continuously and from the number of running R&D projects. Most of the work is realized in the framework of three European research projects. Novopoly project deals with the development of new polymer materials for applications in micro and nano systems. The development of a new EBL resist is framed in this project. Within NaPa, Emerging Nanopatterning methods, the development of NEMS fabrication with EBL is used to realise discrete nanomechanical devices. They are used to characterize the performance of resonating nanostructures and signal enhancement is achieved by their integration in CMOS circuits. The aim of Charpan is the development of a new patterning tool based on several charged particle species. The incidence of charged particle beams on devices is studied to evaluate potential effects induced during fabrication. Carbon nanotube (CNT) based devices contribute to some tasks of national projects Crenatun and Sensonat. In particular, the technology for fabrication of high performance CNT field-effect transistors and their preparation for sensing applications is established.
    [Show full text]
  • High-Throughput Plasmonic Nanolithography
    UC Berkeley UC Berkeley Electronic Theses and Dissertations Title High-Throughput Plasmonic Nanolithography Permalink https://escholarship.org/uc/item/93c7w34j Author Pan, Liang Publication Date 2010 Peer reviewed|Thesis/dissertation eScholarship.org Powered by the California Digital Library University of California High-Throughput Plasmonic Nanolithography by Liang Pan A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Engineering-Mechanical Engineering in the Graduate Division of the University of California, Berkeley Committee in charge: Professor David B. Bogy, Co-Chair Professor Xiang Zhang, Co-Chair Professor Roberto Horowitz Professor Ming Wu Fall 2010 High-Throughput Plasmonic Nanolithography ©2010 by Liang Pan Abstract High-Throughput Plasmonic Nanolithography by Liang Pan Doctor of Philosophy in Engineering-Mechanical Engineering University of California, Berkeley Professor David B. Bogy, Co-Chair Professor Xiang Zhang, Co-Chair The conventional projection-type photolithography approach to nanoscale manufacturing is facing possibly insurmountable challenges, especially to invent novel technical solutions that remain economical for the next generation of semi-conductor integrated circuits. Although extreme ultra violet (EUV) lithography with the next generation photo-masks and 193-nm immersion lithography with double patterning are expected to deliver 22 nm and smaller nodes, it still cannot effectively address the reliability and cost issues required for mass production. Maskless nanolithography is a potentially agile and cost effective approach, but most of the current solutions have throughputs that are too low for manufacturing purposes. This dissertation reports a new low-cost high-throughput approach to maskless nanolithography that uses an array of plasmonic lenses (PL) that "fly" above the rotating surface to be patterned, concentrating short wavelength surface plasmons into sub-100 nm spots.
    [Show full text]
  • And Nanolithography Techniques and Their Applications
    Review on Micro- and Nanolithography Techniques and their Applications Alongkorn Pimpin* and Werayut Srituravanich** Department of Mechanical Engineering, Faculty of Engineering, Chulalongkorn University, Pathumwan, Bangkok 10330, Thailand E-mail: [email protected]*, [email protected]** Abstract. This article reviews major micro- and nanolithography techniques and their applications from commercial micro devices to emerging applications in nanoscale science and engineering. Micro- and nanolithography has been the key technology in manufacturing of integrated circuits and microchips in the semiconductor industry. Such a technology is also sparking revolutionizing advancements in nanotechnology. The lithography techniques including photolithography, electron beam lithography, focused ion beam lithography, soft lithography, nanoimprint lithography and scanning probe lithography are discussed. Furthermore, their applications are summarized into four major areas: electronics and microsystems, medical and biotech, optics and photonics, and environment and energy harvesting. Keywords: Nanolithography, photolithography, electron beam lithography, focused ion beam lithography, soft lithography, nanoimprint lithography, scanning probe lithography, dip-pen lithography, microsystems, MEMS, nanoscience, nanotechnology, nano-engineering. ENGINEERING JOURNAL Volume 16 Issue 1 Received 18 August 2011 Accepted 8 November Published 1 January 2012 Online at http://www.engj.org DOI:10.4186/ej.2012.16.1.37 DOI:10.4186/ej.2012.16.1.37 1. Introduction For decades, micro- and nanolithography technology has been contributed to the manufacturing of integrated circuits (ICs) and microchips. This advance in the semiconductor and IC industry has led to a new paradigm of the information revolution via computers and the internet. Micro- and nanolithography is the technology that is used to create patterns with a feature size ranging from a few nanometers up to tens of millimeters.
    [Show full text]
  • Nano-Lithography
    15-398 Introduction to Nanotechnology Pushing The Limits of Photolithography • Reduce wavelength (λ) Nanoscale Lithography • Use Reducing Lens • Increase Numerical Aperture (NA) of Lens Seth Copen Goldstein – E.g., Immersion optics [email protected] •Hacks (k1) CMU – PSM, OPC, RET, off-axis illumination • Rayleigh eqn: min-feature-size=k1λ/NA lecture 4 © 2004-5 Seth Copen Goldstein 1 lecture 4 © 2004-5 Seth Copen Goldstein 2 Trends in λ, NA, k1 NA & Immersion ICKnowledge.com • NA = n sinα = d/(2f) – N is index of refraction of medium – α is angle of acceptance •Air, n=1 • Water, n≅1.47 • Result -> improve min linewidth 30%! CUHG, Chap 5. lecture 4 © 2004-5 Seth Copen Goldstein 3 lecture 4 © 2004-5 Seth Copen Goldstein 4 E-Beam? FIB? Example of E-beam patterning • Use high-energy electrons to alter/ablate a resist P = 40 nm P = 45 nm • Issues: – Secondary electrons – Scattering in resist (or off substrate) – Serial process P = 50 nm P = 60 nm – alignment Handbook of Microlithography, Micromachining and lecture 4 © 2004-5 Seth Copen Goldstein Microfabrication, SPIE (1997)5 lectureUofA, 4 Nanolithography © 2004-5 Seth Copen Goldstein 6 Microelectronics isn’t everything Today • Reactive organics • Soft Lithography/Nanoimprint • 3-D structures • Scanning Probe Lithography • Edge Lithography • Top-down fabrication to create nanoscale features using a physical mold or tip for patterning. lecture 4 © 2004-5 Seth Copen Goldstein 7 lecture 4 © 2004-5 Seth Copen Goldstein 8 Soft Litho Basic Example • Replica Molding transfer features from master to
    [Show full text]
  • Nanolithography
    Chapter 8 Nanolithography Gunasekaran Venugopal and Sang-Jae Kim Additional information is available at the end of the chapter http://dx.doi.org/10.5772/55527 1. Introduction Nanolithography is the branch of nanotechnology concerned with the study and application of the nanofabrication of nanometer-scale structures, meaning nanopatterning with at least one lateral dimension between the size of an individual atom and approximately 100 nm. The term nanolithography is derived from the Greek words “nanos”, meaning dwarf; “lithos”, meaning rock or stone; and “graphein” meaning to write. Therefore the literal translation is "tiny writing on stone", however nowadays one understands something different whenever this term is associated with nanotechnology. Nanolithography is used e.g. during the nano‐ fabrication of leading-edge semiconductor integrated circuits (nanocircuitry), for nanoelec‐ tromechanical systems (NEMS) or for almost any other fundamental application across various scientific disciplines in nanoresearch. This technology can be suitable to use in nanofabrication of various semiconducting Integrated Circuits (ICs), NEMS and for various applications in research. The modification in semicon‐ ductor chips at the nano-scale (in the range of 10-9 meter) is also possible. This method is contrasting to various existing nanolithographic techniques like Photolithography (Venugo‐ pal, 2011), Nanoimprint lithography (NIL), Scanning Probe Lithography (SPL), Atomic Force Microscope (AFM) nanolithography, Extreme Ultraviolet Lithography (EUVL) and X-ray Lithography. In this chapter, the various nanolithographic fabrication techniques will be discussed in detail in which we will focus the various nano-patterning techniques/procedures suitable for device fabrication and their engineering applications. This technique is mainly used for nanofabrica‐ tion.
    [Show full text]
  • Nano Materialsmaterials
    NanoNano MaterialsMaterials 1 Nanomaterials ContentsContents Introduction Basics Synthesis of Nano Materials Fabrication of Nano Structure Nano Characterization Properties and Applications 2 Nanomaterials FabricationFabrication ofof NanoNano StructureStructure Lithographic techniques Nanomanipulation and nanolithography Soft lithography Self-assembly of nanoparticles or nanowires Other methods Quantum dots 3 Nanomaterials FabricationFabrication ofof NanoNano StructureStructure--lithographylithography - Lithography - Photolithography - Phase shift optical lithography - Electron beam lithography - X-ray lithography - Focused ion beam lithography - Neutral atomic beam lithography 4 Nanomaterials FabricationFabrication ofof NanoNano StructureStructure--lithographylithography Lithography - photoengraving - process of transferring a pattern into a reactive polymer film, termed at resist, which will subsequently be used to replicate that pattern into underlying thin film or substrate Lithography stone and mirror-image print of a map of Munich. 5 Nanomaterials http://en.wikipedia.org/wiki/Lithography http://www.chromaticity.com.au/Glossary/Lithography.GIF FabricationFabrication ofof NanoNano StructureStructure--lithographylithography Photo-lithography - basic steps - shadow printing- contact printing proximity printing projection printing 6 Nanomaterials J.D. Plummer, Silicon VLSI Technology, 2000. G. Cao, Nanostructures and Nanomaterials, 2004. FabricationFabrication ofof NanoNano StructureStructure--lithographylithography Photo-lithography
    [Show full text]
  • Studying of Various Nanolithography Methods by Using Scanning Probe Microscope
    Int.J.Nano.Dim 1(3): 159-175, Winter 2011 ISSN: 2008-8868 Review Studying of various nanolithography methods by using Scanning Probe Microscope S. Sadegh Hassani* and Z. Sobat Nanotechnology research center, Research institute of petroleum industry (RIPI), Tehran, Iran Received: 5 November 2010; Accepted: 20 January 2011 Abstract The Scanning Probe Microscopes (SPMs) based lithographic techniques have been demonstrated as an extremely capable patterning tool. Manipulating surfaces, creating atomic assembly, fabricating chemical patterns, imaging topography and characterizing various mechanical properties of materials in nanometer regime are enabled by this technique. In this paper, a qualified overview of diverse lithographical methods mostly based on making nano-structures is presented. Keywords: Nano-lithography, Atomic force Microscopy, Scanning probe lithography, nanostructure, surface nano-modification. 1. Introduction Recently, the interest to nanometer scale designed useful structures in the science and technology is rapidly increased, and these technologies will be superior for the fabrication of nanostructures [1].The patterning of materials in this scale face with great importance (for) in future lithography in order to attain higher integration density for semiconductor devices. The emergence of nano-science and nanotechnology depends on the ability to posit, manipulate and fabricate a variety of structures, materials and devices with the accuracy in the nano-meter scale. Conventional lithography techniques, i.e., those divided to optical and electron beam lithography are either cost- intensive or unsuitable to handle the large variety of organic and biological systems available in nanotechnology. Various driving forces have been considered for development of alternative nanofabrication techniques [2-3].These techniques have been established approximately in 1990 and then they have given rise to the establishment of three major nanolithography methods: * Corresponding author: S.
    [Show full text]
  • Electron Beam Lithography Fabrication of SU-8 Polymer Structures for Cell Studies
    bioRxiv preprint doi: https://doi.org/10.1101/849745; this version posted November 21, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. Electron beam lithography fabrication of SU-8 polymer structures for cell studies Jakob Vinje,∗,† Kai S. Beckwith,‡ and Pawel Sikorski† †Department of Physics, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway ‡Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway E-mail: [email protected] Abstract Flat surfaces decorated with micro- and nanostructures are important tools in biomedical research used to control cellular shape, in studies of mechanotransduction, membrane mechanics, cell migration and cellular interactions with nanostructured surfaces. Existing methods to fabricate surface-bound nanostructures are typically limited either by resolution, aspect ratio or throughput. In this work, we explore electron beam lithography based structuring of the epoxy resist SU-8 on glass substrate. We focus on a systematic investigation of the process parameters and determine limits of the fabrication process, both in terms of spatial resolution, structure aspect ration and fabrication throughput. The described approach is capable of producing high-aspect ratio, surface bound nanostructures with height ranging from 100 nm to 4000 nm and with in-plane resolution below 100 nm directly on a transparent substrate. Fabricated nanostructured surfaces can be integrated with common techniques for biomedical research, such as high numerical aperture optical microscopy. Further more, we show how the described approach can be used to make nanostructures with multiple heights 1 bioRxiv preprint doi: https://doi.org/10.1101/849745; this version posted November 21, 2019.
    [Show full text]
  • Introduction to Nanolithography Introduction to Nanolithography
    Introduction to Nanolithography Junwei Su Mechanical Engineering University of Massachusetts Lowell [email protected] Outline • Introduction • Photolithography • SfSoft Lihithograp hy • Nanoimprint Lithography (NIL) • NIL System Overview • Conclusion Nanolithography Nanolithography is the branch of nanotechnology concerned with the stdtudy and applica tion of fbifabrica ting nanometer‐scale structures, meaning patterns with at least one lateral dimension between the size of an individual atom and approximately 100 nm. Introduction • Why we need micro/nano pattern? MEMS (Micro electronic mechanical system) A MEMS device optical switch ratcheted microgear [Sandia National Laboratories] (Sandia) (Sandia) Top‐down Versus Bottom‐up Top Down Process Bottom Up Process Start with bulk Start with bulk wafer wafer Apply layer of Alteeaeaor area of w aeafer photoresist where structure is to be created by adding polymer or seed Expose wafer with crystals or other UV light through techniques. mask and etch Grow or assemble wafer the structure on the area determined by Etched wafer with the seed crystals or desired pattern polymer. (self assembly) Similar results can be obtained through bottom-up and top-down processes Photolithography https://www.youtube.com/watch?v=1bxf9QRVesQ EUV lithography • Extreme ultraviolet lithography (also known as EUV or EUVL) is a next‐ generation lithography technology using an EUV wavelength, currently expected to be 13.5 nm. Photolithography Limits • It requir es epesexpensive instr um en ts adand facili ti es with high capital investment • Pattern resolution is limited by optical diffraction • The methods is not suitable for patterning all types of polymers, and only photosensitive resist materials can be directly patterned. • The technique requires harsh processing conditions.
    [Show full text]
  • Electron Beam Lithography for Nano-Antenna Fabrication
    ELECTRON BEAM LITHOGRAPHY FOR NANO-ANTENNA FABRICATION A Thesis presented to the Faculty of the Graduate School at the University of Missouri-Columbia In Partial Fulfillment of the Requirements for the Degree Master of Science by PARINAZ EMAMI Dr. Patrick J. Pinhero, Thesis Supervisor JULY 2015 1 The undersigned, appointed by the dean of the Graduate School, have examined the thesis entitled ELECTRON BEAM LITHOGRAPHY FOR NANO- ANTENNA FABRICATION Presented by Parinaz Emami a candidate for the degree of Master of Science and here by certify that in their opinion it is worthy of acceptance. Professor Patrick J. Pinhero Professor Matthew Bernards Professor Sheila Baker 2 I want to dedicate my dissertation to my parents, Mehri Hekmatnavaz and Aliakbar Emami because of their endless support, kindness, and encouragements, I will always appreciate all they have done for me and wish someday, I would be able to pay back a small part of their sacrifices. I also dedicate this work to my sisters, Parnian and Parisa who have always encouraged me to believe in myself and truly supported me in all steps of my life. 3 ACKNOWLEDGMENTS First, I would like to sincerely thank my advisor Dr. Patrick Pinhero, for all of his supports, helps, and wonderful ideas, which cause this thesis to be successful. And also I want to thank Dr. Sheila Baker and Dr. Matthew Bernards who accepted to be in my thesis committee. I also want to thank Zach Thacker who helped me a lot during this process with his thoughtful suggestions, and many thanks to Dr. Tommi White and Thomas Lam for their support and helps during my experiments.
    [Show full text]