1. Introduction to Nanotechnology Module #1 Nanotechnology: What Is It, And Why Is It So “BIG” Now? © patton brothers illustration ( www.pattonbros.com ) Copyright April 2009 The Pennsylvania State University Last Updated: 1/6/2011 Copyright 2009 The Pennsylvania State University Nanotechnology is Impacting Everything

7. Where does the Nanometer fit in the length scale? Copyright April 2009 The Pennsylvania State University 1 meter = 3.28 feet 1 / 100 meter = 1 centimeter (cm) 1 / 1000 meter = 1 millimeter (mm) 1 / 1,000,000 meter = 1 micrometer* ( µm) *also called a micron 1 / 1,000,000,000 meter = 1 nanometer (nm) 1 / 1,000,000,000,000 meter = 1 picometer (pm)

8. Another way of looking at how small a Nanometer is- ©2009 NanoHorizons Inc. Copyright April 2009 The Pennsylvania State University

9. Still another way of looking at how small a Nanometer is- Click on the black box to view Mini Cooper movie Copyright April 2009 The Pennsylvania State University Produced by the Museum of Science, Boston with support from the Nanoscale Informal Science Education Network and the Center for High-rate Nanomanufacturing. © 2007.

11. How Do We See Things in These Different Size Ranges? Meter Size Range These are sizes we can see with just our eyes Millimeter Size Range These are sizes we can see with an optical microscope Micrometer Size Range Bigger objects in this range can be seen with an optical microscope . Smaller objects may need an electron microscope Nanometer Size Range Bigger objects can be seen with electron microscopes. Smaller objects require field emission electron or atomic force microscopes MACRO-SCALE NANO-SCALE MICRO-SCALE Copyright April 2009 The Pennsylvania State University

12. Let’s look at these size ranges pictorially. Let’s also get some idea of what nature makes and what man makes in these size ranges. Copyright April 2009 The Pennsylvania State University

13. Some Small Naturally Occurring and Man-Made Structures 1 mm 100 µm 10 µm 1 µm 100 nm 10 nm 1 nm 100 pm Transistor of 2007 Human hair tissue Bacterium cell Human cell Virus Transistors of 20-30 Years ago Protein Individual atom Drug molecule Quantum dot DNA Nano-scale Micro-scale Macro-scale Copyright April 2009 The Pennsylvania State University Stanford University © 2009 Created by Sean Nash

14. Also note from our pictorial representation of scales that the next size range that is smaller than the nano-scale is the pico-scale. Copyright April 2009 The Pennsylvania State University

17. What’s After Nanotechnology – Is there a Picotechnology? No, nothing to build at the pico-scale. The elements of the universe are fixed in number (and nicely listed in the periodic table) Copyright April 2009 The Pennsylvania State University

19. “ Nanotechnology is the builder’s final frontier.” Richard Smalley 1996 Nobel Laurate in Chemistry, Rice University Smalley Institute for Nanoscale Science & Technology Copyright April 2009 The Pennsylvania State University

26. Adapted from Linda Geppert, The Amazing Vanishing Transistor Act, IEEE Spectrum, October 2002, Vol. 39, Number 10, pg. 28-33 Copyright April 2009 The Pennsylvania State University

29. Quantum Corral IBM Research Division M.F. Crommie, C.P. Lutz, D.M. Eigler. Confinement of electrons to quantum corrals on a metal surface. Science 262, 218-220 (1993). Copyright April 2009 The Pennsylvania State University

31. Introduction to Nanotechnology Module #2 A Brief History of Nanotechnology © patton brothers illustration ( www.pattonbros.com ) Copyright April 2009 The Pennsylvania State University Last Updated: 1/6/2011 Nanotechnology is Impacting Everything

36. Around the year 1100. Arab craftsmen made steel swords of legendary strength. Today we know these swords had carbon nanotubes and nanowires in the material. This is the oldest known use of carbon nanotubes and nanowires. These nanostructures may account for the swords’ strength. Carbon nanotubes and carbon nanowires in Damascus steel sword. Copyright April 2009 The Pennsylvania State University Reibold, M., et al. "Carbon Nanotubes in an Ancient Damascus Sabre." Nature 444 (2006).

37. Reprinted with permission from Journal of Applied Physics, Vol. 93, Issue 12, P.10058, 2003, American Institute of Physics. 16 th century Renaissance pottery Around the year 1500. The Renaissance Italians used what we now know to be copper and silver nanoparticles to achieve this vibrantly colored pottery. Again, we don’t know the details of how they did it. Copyright April 2009 The Pennsylvania State University

42. In 1931. Ruska Develops the Transmission Electron Microscope (TEM)--- The beginnings of being able to really “SEE” at the nanoscale The transmission electron microscope has become a very powerful tool for “seeing” at the nano-scale. Copyright April 2009 The Pennsylvania State University

45. In 1959. Richard Feynman gives his famed talk “There is Plenty of Room at the Bottom” “ What I want to talk about is the problem of manipulating and controlling things on a small scale.” In this talk, Feynman said that we have progressed to the point where we can and should manipulate matter at what today we call the nano-scale. Copyright April 2009 The Pennsylvania State University Richard Feynman © 1965

46. He uses it to signify machining with tolerances of less than a micron (1000 nanometers). Today the term nanotechnology has evolved to mean making and manipulating “ things” that are much smaller! Today the “things” of nanotechnology have at least one dimension in the range of 1nm to about 100nm. In 1974. Norio Taniguchi coins the word “nanotechnology”. Copyright April 2009 The Pennsylvania State University

48. In 1981. Gerd Binnig and Heinrich Rohrer invent the first of the scanning probe tools- -- the scanning tunneling microscope. With this tool, we now could see individual atoms! With the invention of the scanning tunneling microscope , we can now “see” atoms Reprint Courtesy of International Business Machines Corporation copyright © International Business Machines Corporation. Figure: Michael Schmid, TU Wien Copyright April 2009 The Pennsylvania State University

50. In 1989. Donald M. Eigler of IBM “writes” for the first time with individual atoms Scanning probe tools (specifically the atomic force microscope (AFM)) can be used to drag atoms into preselected positions. Atoms aren’t blue nor are they cones. The color is computer rendering and shape is artifact of AFM. Copyright April 2009 The Pennsylvania State University Reprint courtesy of International Business Machines Corporation, copyright © 1990 International Business machines Corporation

51. In 1986. Eric Drexler publishes: “ Engines of Creation” Science fiction interest in nano begins Copyright April 2009 The Pennsylvania State University

52. In 1991. Sumio Iijima of NEC in Tsukubaka, Japan, discovered carbon nanotubes . Another unique carbon bonding configuration tolerated by nature only at the nano-scale . Copyright April 2009 The Pennsylvania State University Image Courtesy of NEC © Queen's University 2007

54. In 1998. Cees Dekker’s group at the Delft University of Technology demonstrates a transistor made from a carbon nanotube Courtesy C. Dekker, Delft University Copyright April 2009 The Pennsylvania State University J. Appenzeller, J. Knoch, R. Martel, V. Derycke, S. Wind, Ph. Avouris, Short-channel like effects in Schottky barrier carbon nanotube field-effect transistors, IEEE Technical Digest 2002. p.285. (© 2002 IEEE)

55. In 1999. Tour (Rice University) and Reed (Yale University) demonstrate single molecules can act as switches turning electric current on and off, giving experimental support for the idea of “Molecular Electronics” Original arrangement Molecule rearranged The molecule’s physical arrangement depends on the voltage on the contacts. Voltages above a threshold value cause rearrangement of the molecule and thus change the current it can carry. Copyright April 2009 The Pennsylvania State University Courtesy Mark Reed. Yale University. 1997 molecule Contacts

61. Copyright April 2009 The Pennsylvania State University Introduction to Nanotechnology Module #3 A Snapshot of Nanotechnology Today Nanotechnology is Impacting Everything © patton brothers illustration ( www.pattonbros.com ) Last Updated: 1/6/2011

64. Nanotechnology Investments Government, Corporation, and Venture Capitalist Investments Copyright April 2009 The Pennsylvania State University

85. The Product: Quantum dots These are available commercially and used in, for example, medical research for their very strong fluorescence color. The color they give off when excited can be changed simply by buying different sized dots which changes Δ E and thereby the fluorescing color. This picture of vials containing actual quantum dots was captured after the samples were placed in front of a UV hand lamp which excited the electrons from below E 1 to above E 2 . Product Example # 3 (continued) “ Relative Size of a Qdot® Nanocrystal.” Invitrogen Corporation . 2009. Copyright April 2009 The Pennsylvania State University

87. A Single-wall Carbon Nanotube The carbon atoms are the balls Copyright April 2009 The Pennsylvania State University

89. The product: Easton, a company that makes bicycles, is using carbon nanotubes in bikes they have on the market. Easton has a full carbon-fiber frame bicycle. This frame gives excellent weight savings, ride quality, and strength levels. The frame is a full CNT based material. In fact, the only metal part is the BB thread alloy insert . www.pezcyclingnews.com Product Example # 4 (continued) Copyright April 2009 The Pennsylvania State University

90. www.pezcyclingnews.com Copyright April 2009 The Pennsylvania State University

92. The very high surface to volume ratio of nanoparticles Lower surface Higher surface to volume ratio to volume ratio Copyright April 2009 The Pennsylvania State University Courtesy of CNEU

96. A silver nanoparticle attached to a textile fiber Copyright April 2009 The Pennsylvania State University © 2009 NanoHorizons Inc.

97. The Product: A number of companies are manufacturing and selling shoes and clothing containing silver nanoparticles for odor control. Product Example # 5 (continued) Copyright April 2009 The Pennsylvania State University

101. Adapted from Linda Geppert, The Amazing Vanishing Transistor Act, IEEE Spectrum, October 2002, Vol. 39, Number 10, pg. 28-33 Copyright April 2009 The Pennsylvania State University

104. The Product: Companies are manufacturing microelectronics circuits with more speed and more functionality due to the nanoscale transistors used in these circuits. Product Example # 6 (continued) Copyright April 2009 The Pennsylvania State University Copyright Matco Services Inc. www.materialsforum.com Mick Feuerbacher, December 2005.

109. Introduction to Nanotechnology Module #4 The Uniqueness of the Nano-scale © patton brothers illustration ( www.pattonbros.com ) Copyright April 2009 The Pennsylvania State University Last Updated: 1/6/2011 Nanotechnology is Impacting Everything

116. An example of an impact of this attribute: Huge Areal Densities The huge number of nano-scale transistors possible per area means today’s state-of-the-art microelectronics circuits with their nano-scale transistors can give more speed and more functionality. Copyright April 2009 The Pennsylvania State University Mick Feuerbacher, December 2005. Copyright Matco Services Inc. www.materialsforum.com

117. High surface to volume ratio Ratio = 3/R This ratio is very big when R is very small Ratio = 4 π R 2 _ 4/3 π R 3 Copyright April 2009 The Pennsylvania State University R

118. Impact of the Huge Surface to Volume Ratio Percent Surface Atoms Diameter (nm) This figure shows the inverse relationship between particle size and number of surface atoms. As a particle gets smaller, a larger and larger percentage of the atoms that make up the particle are surface atoms. Because the number of atoms or molecules on the surface of a particle influences the particle’s chemical and physical interactions with its environment, this percentage in the figure is key to defining the chemical and biological properties of nanoparticles. Figure 1 from Andre Nel, Tian Xia, Lutz Mädler and Ning Li ., SCIENCE Vol.311. p. 622 (2006). Copyright April 2009 The Pennsylvania State University

119. Reprinted figure with permission from Buffat and Borel, “Phys Rev. A” Volume 13, p 2287 (1976). Copyright 1976 by the American Physical Society. An example of an impact of this attribute: Melting Temperature This data is for Gold The melting temperature gets lower as a nanoparticle gets smaller because higher percentage of atoms are on the surface. This makes sense since surface atoms are not bound to each other the same way bulk atoms are. Particle diameter in Angstroms Copyright April 2009 The Pennsylvania State University

122. An example of an impact of this attribute: Colloidal Solutions The nano-scale colloidal particles in the solutions seen above will never settle out. (so long as surface forces are not present to cause them to agglomerate. If they agglomerated, this would increase particle volume and give gravity a chance to become important) Copyright April 2009 The Pennsylvania State University “ Electronic Imaging & Signal Processing: Improving biomedical imaging with gold nanocages” by Younan Xia and Sara E. Skrabalak. 12 May 2008, SPIE Newsroom. DOI: 10.1117/2.1200705.1135

124. An example of an impact of this attribute: Semiconductor Quantum Dots When excited by light, quantum dots fluoresce (re-emit light). The size and material composition of nano-scale quantum dots dictates the color they re-emit. Copyright April 2009 The Pennsylvania State University Evidenttech.com

126. An example of an impact of this attribute: Photonic Crystals Man-made nano-structures can cause light to turn sharp 90 degree corners, as seen below Copyright April 2009 The Pennsylvania State University Reproduced with permission of the MRS Bulletin. www.mrs.org/bulletin

127. Butterfly Scales 20,000 x magnification 5000x magnification 220x magnification 1x magnification of wing Another example of an impact of this attribute Nanostructures can cause light of different colors to scatter and diffract differently. This effect is used by nature to give the colors seen in butterfly wings. Militaries Study Animals for Cutting-Edge Camouflage. James Owen in England for National Geographic News March 12, 2003, Proc. R. Soc. Lond. B (1999) 266, 1403-1411 Copyright April 2009 The Pennsylvania State University

129. The cell is a complex structure with many compartments and organelles possessing individual and interdependent functions. Many of a cell`s features (e.g., pores) and, of course, DNA and RNA are all in the nano-scale. We can now make structures like these smallest of features in a cell. An example of an impact of this attribute: Copyright April 2009 The Pennsylvania State University Public Library of Science, “The Intersection of Biology and Materials Science” by George M. Whitesides and Amy P. Wong Vol. 31, p. 23.

130. Golovchenko, Branton, et. al. (Harvard Nanopore Group) Sequencing DNA using nanopore ionic conductance. Another Example: Structures that can “read” DNA Can now make structures so small that they, for example, can force DNA to line-up single file in order to pass through We can now use electrical signal changes to “read” the DNA as it passes through DNA Copyright April 2009 The Pennsylvania State University

131. DNA: millions of atoms long but 2.5 nm wide Nanostructures can have the dimensions seen in macromolecules Copyright April 2009 The Pennsylvania State University The Chaim Weizmann Institute of Chemistry, and the Fritz Haber Research Center for Molecular Dynamics, The Hebrew University of Jerusalem.

132. We can now make man-made versions of Nature`s motors like this one. Here Myosin V (blue), a cellular motor protein, carries cargo within cells by moving along actin filaments (red). It takes 37 nanometer steps by placing one “foot” over the other, as revealed by a fluorophore tag (rainbow-colored oval). [Illustration: PrecisionGraphics.com] Ahmet Yildiz, Joseph N. Forkey, Sean A. McKinney, Taekjip Ha, Yale E. Goldman, Paul R. Selvin: Myosin V Walks Hand-Over-Hand: Single Fluorophore Imaging with 1.5-nm Localization . Science. 2003. Vol. 300. p.2061 An example of an impact of this attribute: Copyright April 2009 The Pennsylvania State University

133. Unique chemical bonding configurations possible Carbon nanotubes Copyright April 2009 The Pennsylvania State University Odom et al, J. Phys. Chem. B104, 2794 (2000). Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

134. An example of an impact of this attribute Superior strength concrete for construction made with CNTs Carbon nanotubes distributed on small cement grains Copyright April 2009 The Pennsylvania State University S Bulletin, Vol. 31. P. 23, January 2006 Makar, J. M Beaudoin, J.J/NRCC-46618 http://irc.nrc-cnrc.gc.ca/ircpubs . Reproduced with the permission of the Minister of Public Works and Government Services Canada, 2009.

135. Molecular Self-Assembly An example: a mixture of two polymeric molecules can be made to self-assemble, under the influence of heat, into a structure with one phase made up only of molecules of type 1 and another phase made up only of molecules of type 2 White phase (regions) is made up only of molecules of type 1 Black phase (regions) is made up only of molecules of type 2 Copyright April 2009 The Pennsylvania State University Courtesy of CNEU

136. New Ways of Seeing things The nano-scale tips on scanning probe microscopes (SPMs) allow us to even “see” atoms Actual Atoms! IBM Research Division M.F. Crommie, C.P. Lutz, D.M. Eigler. Confinement of electrons to quantum corrals on a metal surface. Science 262, 218-220 (1993). Copyright April 2009 The Pennsylvania State University

138. Introduction to Nanotechnology Module #5 How Do We “See” Things at the Nano-scale: An Introduction to Characterization Techniques Nanotechnology is Impacting Everything © patton brothers illustration ( www.pattonbros.com ) Copyright April 2009 The Pennsylvania State University Last Updated: 1/6/2011

145. Schematic of a TEM or FE-TEM JEOL 2010F Semiconductor Material and Device Characterization, 3 rd ed. Dieter K. Schroder, John Wiley & Sons, Inc. p 647. 1999 Copyright April 2009 The Pennsylvania State University

146. Size, Shape, and Structure Observations using a TEM Here a silver nanowire is seen at various levels of magnification and finally, on the right, at a magnification that resolves the individual atoms (The Ag atoms appear as the white “dots”) Copyright April 2009 The Pennsylvania State University © 2005 College of Engineering at The University of Texas at Austin. Nanoscale Materials: Metal Nanowires

148. SEM Operation Click on the image to view the movie Copyright April 2009 The Pennsylvania State University SEM Images and Text Courtesy of the Museum of Science, Boston

149. A Size and Shape Observation using an SEM A carbon nanotube Copyright April 2009 The Pennsylvania State University Copyright 2006-2009 JEOL Ltd.

153. A Size, Shape, and Composition Observations using X-rays Imaging Technology Group, Beckman Institute of Advanced Science and Technology, University of Illinois Copyright April 2009 The Pennsylvania State University Ni Colors assigned to different elements C Ca Na SEM Image of a grain of sand showing well defined regions Composition mapping (of the regions seen in the SEM micrograph) using X-rays

156. SPM Tools All Use a Probe with a Nano-scale Sized Tip Copyright April 2009 The Pennsylvania State University Image courtesy: Greg McCarty tip sample

159. Deflection of the cantilever due to varying forces between the nano-scale tip and the atoms of the surface is picked up by changes in the laser beam reflection and converted by a computer into a picture. Copyright April 2009 The Pennsylvania State University

160. AFM Operation Movie courtesy of Veeco Instruments Inc. Tapping mode Click on the black box to view the movie Copyright April 2009 The Pennsylvania State University

161. Size and Shape Observations using an AFM Seeing DNA using an AFM Copyright April 2009 The Pennsylvania State University Courtesy of SPMage. http://www.icmm.csic.es/spmage/ "Toroidally supercoiled DNA” Dr. Jozef Adamcik. Ecole Polytechnique Federale de Lausanne (EPFL). S witzerland

162. AFM Probes can be used to move Nano-particles Copyright April 2009 The Pennsylvania State University Courtesy of CNEU

164. Picture of the Atoms on a Silicon Surface Imaged using STM Atoms on a silicon surface. Note that you can see that Nature has made some mistakes and there are defect sites where atoms are missing. Scanning tunneling microscopes allow surfaces to be imaged at the atomic-scale Schematic of the scanning tunneling microscope Image courtesy: Greg McCarty Copyright April 2009 The Pennsylvania State University

165. STM Probes can also be used to move Individual Atoms or Molecules Using Voltages applied between the Tip and the selected Atom or Molecule Copyright April 2009 The Pennsylvania State University Courtesy of CNEU

166. Here atoms on a surface are being arranged by an STM to form a corral Don Eigler and co-workers at IBM published these greyscale STM images showing the moving of atoms across a surface to form a corral as the corral was being constructed. The atoms were moved by the STM also by applying voltages to the probe that attracted the atom during the moving process. The atoms that form the surface itself can be seen in these STM images lying below those atoms in the process of being moved. Some Corral Atoms are in Position Atoms in various Stages of Being Moved Atoms of the Underlying Surface Finished Corral Copyright April 2009 The Pennsylvania State University Science 1993

167. A Quantum Corral As Seen By STM The STM tunneling current has been turned by a computer into this false color STM image of the Quantum Corral. The computer also tilted the image for us. Copyright April 2009 The Pennsylvania State University Science 1993

172. Introduction to Nanotechnology Module #6 How Do You Make Things So Small? An Introduction to Nanofabrication © patton brothers illustration ( www.pattonbros.com ) Copyright April 2009 The Pennsylvania State University Last Updated: 1/6/2011 Nanotechnology is Impacting Everything

174. Making nano-scale “things” is called Nanofabrication Copyright April 2009 The Pennsylvania State University

187. Top-down Nanofabrication is like Sculpting Start with a material supported on a substrate Add some new material according to a pattern (lithography) Copyright April 2009 The Pennsylvania State University Image courtesy of Bruce Hirst Image courtesy of Bruce Hirst

188. Top-down Nanofabrication is like Sculpting Subtract some of the material according to a pattern (Process order is not important; can subtract before or after adding) Repeat the adding/subtracting as needed following the pattern Copyright April 2009 The Pennsylvania State University Image courtesy of Bruce Hirst Image courtesy of Bruce Hirst

189. Bottom-up Nanofabrication is like putting blocks together The building blocks can go together in some inherent pattern dictated by shape or they can go together randomly. The building blocks can be atoms, molecules, or nanoparticles Copyright April 2009 The Pennsylvania State University

195. Etching Lithography Depositing or Growing Material Modification The Top-down Fabrication Methodology Copyright April 2009 The Pennsylvania State University Courtesy of CNEU

197. An Example of a Top-Down Nanofabrication Processing Sequence Copyright April 2009 The Pennsylvania State University Film Grown by Chemical Reaction of Ambient species with the Substrate Thin Film Substrate Photoresist PLASMA ETCH + IONS + IONS + IONS LITHOGRAPHY ETCHING Chemistry Chemistry Chemistry Spin on Photoresist Align Photomask Expose with Light Chemical Bonds are Altered in Exposed Areas Dissolve Exposed Photoresist in Liquid Developer Remove the Photoresist (Etch/Ion Implantation) Barrier (Negative Bias) Pattern Transfer and Substrate Modification Complete HEAT Substrate THIN FILM GROWTH OR DEPOSITION Oxygen SURFACE MODIFICATION + + + + + + + Ion Implantation Thermal Anneal HEAT Mask

202. Building Block Fabrication Self Assembly The Bottom-up Fabrication Methodology Copyright April 2009 The Pennsylvania State University Courtesy of CNEU

204. An Example of a Bottom-Up Nanofabrication Processing Sequence Functionalize the Nanoparticle Link with Antibodies Antigen Attachment Synthesize Nanoparticle Copyright April 2009 The Pennsylvania State University Courtesy of CNEU

206. Introduction to Nanotechnology Module #7 How Do You Build Things So Small: Top-Down Nanofabrication Copyright April 2009 The Pennsylvania State University © patton brothers illustration ( www.pattonbros.com Last Updated: 1/6/2011 Nanotechnology is Impacting Everything

208. Top-down Nanofabrication is like Sculpting Start with a material supported on a substrate (or just start with the substrate) Add some new material according to a pattern (lithography; i.e., pattern transfer) Copyright April 2009 The Pennsylvania State University Image courtesy of Bruce Hirst Image courtesy of Bruce Hirst

209. Top-down Nanofabrication is like Sculpting Subtract some of the material according to a pattern (Process order is not important; can subtract before or after adding) Repeat the adding/subtracting as needed following the pattern Copyright April 2009 The Pennsylvania State University Image courtesy of Bruce Hirst Image courtesy of Bruce Hirst

212. Etching Lithography Depositing or Growing Material Modification The Basic Steps of Top-down nanofabrication. These are used in any sequence. Copyright April 2009 The Pennsylvania State University Courtesy of CNEU

213. An Example of a Top-Down Nanofabrication Processing Sequence Copyright April 2009 The Pennsylvania State University Film Grown by Chemical Reaction of Ambient species with the Substrate Thin Film Substrate Photoresist PLASMA ETCH + IONS + IONS + IONS LITHOGRAPHY ETCHING Chemistry Chemistry Chemistry Spin on Photoresist Align Photomask Expose with Light Chemical Bonds are Altered in Exposed Areas Dissolve Exposed Photoresist in Liquid Developer Remove the Photoresist (Etch/Ion Implantation) Barrier (Negative Bias) Pattern Transfer and Substrate Modification Complete HEAT Substrate THIN FILM GROWTH OR DEPOSITION Oxygen SURFACE MODIFICATION + + + + + + + Ion Implantation Thermal Anneal HEAT Mask

214. In the preceding cartoon sequence, all 4 steps were used. Sometimes, one or more of these steps is not needed and is omitted in nanofabrication. Copyright April 2009 The Pennsylvania State University

218. Material modification Deposition or growth of films/layers Lithography (pattern transfer) Etching (material removal) The Top-down nanofabrication methodology Deposition or Growth Step Copyright April 2009 The Pennsylvania State University Courtesy of CNEU

220. Growth by Chemical Reaction Thin Film Substrate HEAT Substrate (This Example Shows Oxidation) Film Grown by Chemical Reaction of Ambient species with the Substrate Oxygen Copyright April 2009 The Pennsylvania State University Courtesy of CNEU

221. Growth by chemical reaction differs from physical application, physical vapor deposition, and chemical vapor deposition in that part of the layer is used up (chemically reacted) in any growth process. Copyright April 2009 The Pennsylvania State University

222. Physical Application There are many types of physical application processes; e.g., dipping, spraying, and spin-on. Here we see layer spin-on in cartoon form. Thin Film Substrate Layer Substrate Copyright April 2009 The Pennsylvania State University Courtesy of CNEU

223. Physical Vapor Deposition (PVD) In this example of PVD called sputtering , a film (purple) is being deposited on the substrate by argon ions (green). These ions act as hammers knocking film atoms (yellow) off the target (yellow too). A negative voltage attracts the Ar ions to the target . Copyright April 2009 The Pennsylvania State University Courtesy of CNEU

224. Chemical Vapor Deposition (CVD) In this example of CVD, gas molecules (the precursor) are broken apart by a plasma. The radicals, ions, and electrons produced result in a chemical reaction on the substrate producing the creation of a film as shown . Copyright April 2009 The Pennsylvania State University Courtesy of CNEU Ω ~ Impedance Match AC Power Source Throttle Valve Silane Plasma Si Amorphous silicon film growing H Gas Inlet #1 Gas Inlet #2

226. Material modification Deposition or growth of films/layers Lithography (pattern transfer) Etching (material removal) The top-down nanofabrication methodology Lithography (pattern transfer) Lithography Step Copyright April 2009 The Pennsylvania State University Courtesy of CNEU

229. The controlling pattern that is “written” to guide the fabrication processes permanently resides in a “ mask ”, in a mold , or in an computer data file , depending on the type of lithography. A mask is a plate of transparent material (e.g., glass) on which a pattern resides. A mold is a plate in which a pattern resides Copyright April 2009 The Pennsylvania State University

230. Basic Terms used in Lithography Lithography – The transferring (writing) of a pattern-usually to a “resist” Resist – Medium into which pattern on a mask, on a mold, or in computer file is transferred. Used in most types of lithography Developer – Needed in some types of lithography to bring out the pattern written in the resist Copyright April 2009 The Pennsylvania State University

231. There are many types of lithography Copyright April 2009 The Pennsylvania State University Type of Lithography Initial Location of Pattern “ Pencil” Doing the Writing Resist Used? Developer Used? Photo-lithography Mask Flood of light (photons) Yes Yes Electron Beam Lithography Data File Beam of Electrons Yes Yes Ion Beam Lithography Data File Beam of Ions Yes Yes Dip Pen Lithography Data File Physical Contact No No Embossing Lithography Mold Physical Contact Yes, usually If resist used Flash Mold Physical Contact Yes etching Stamp Lithography Mold Physical Contact Can be If resist used Molding Lithography Mold Deposited Material Can be If resist used Self-Assembly Lithography Mask, Mold, or Data File Deposited Material Can be If resist used

233. Photo (or Optical ) Lithography Copyright April 2009 The Pennsylvania State University

234. Photo (or Optical) Lithography Mask (pattern is on the mask) Resist Substrate Visible or UV light Resist, which has been coated onto the substrate, is exposed to light—but only in regions allowed by the mask Copyright April 2009 The Pennsylvania State University Courtesy of CNEU

235. Photo Lithography (continued) Exposed photo-resist has been designed to have its chemical bonding changed in the regions exposed to light Copyright April 2009 The Pennsylvania State University Courtesy of CNEU

236. Photo Lithography (continued) These changed regions are then chemically attacked by a developer and removed. Copyright April 2009 The Pennsylvania State University Courtesy of CNEU

237. Photo Lithography (continued) The result of the chemical attack by the developer is that the pattern is now “written” in the resist Copyright April 2009 The Pennsylvania State University Courtesy of CNEU

239. Photo Lithography (continued) The pattern is put into the substrate by using the resist as a chemical-attack barrier and etching the substrate. After etching, the resist is removed and the pattern is now in the substrate. Copyright April 2009 The Pennsylvania State University Courtesy of CNEU

240. Dip Pen Lithography Another Example of a Type of Lithography Copyright April 2009 The Pennsylvania State University

241. Dip Pen Nanolithography - An AFM probe tip is used to write alkanethiols (a type of molecule) onto a surface -Writes sub – 100 nm features - Moving the probe tip can be slow. Manufacturing through-put problem? S. Hong and C.A. Mirkin, Northwestern University Center for Nanofabrication and Molecular Assembly Copyright April 2009 The Pennsylvania State University

242. Embossing (or Nano-imprinting ) Lithography Another Example of a Type of Lithography Copyright April 2009 The Pennsylvania State University

243. Copyright April 2009 The Pennsylvania State University Courtesy of CNEU

244. Copyright April 2009 The Pennsylvania State University Courtesy of CNEU

245. Structures Produced using Patterns Created by Embossing Lithography Followed by Etching Copyright April 2009 The Pennsylvania State University "Current Status of Nanonex Nanoimprint Solutions," Hua Tan, Linshu Kong, Mingtao Li, Colby Steer and Larry Koecher, SPIE, (2004) "Four-inch Photo-Curable Nanoimprint Lithography Using NX-2000 Nanoimprint," Mingtao Li, Hua Tan, Linshu Kong, and Larry Koecher, SPIE, (2004)

246. Another example of