Nanotechnology Past Present and Future STEM ED UMass

Nanotechnology: Past, Present, and Future STEM ED UMass March 29, 2008

Introduction to Nanotechnology: What, Why and How bnl manchester UMass Amherst Nanoscale Science and Engineering Center

Nanotechnology: What?

Nanotechnology is the understanding and control of matter at dimensions of roughly 1 to 100 nanometers, where unique phenomena enable novel applications. 1 nanometer = 1 billionth of a meter = 1 x 10 -9 m nano. gov

How small are nanostructures? Single Hair Width = 0. 1 mm = 100 micrometers = 100, 000 nanometers ! 1 nanometer = one billionth (10 -9) meter

Smaller still Hair 6, 000 nanometers DNA . Red blood cell 3 nanometers

From DOE

A Few Nanostructures Made at UMass 100 nm dots 18 nm pores 70 nm nanowires 12 nm pores 14 nm nanowires 13 nm rings 200 nm rings 14 nm dots 25 nm honeycomb 150 nm holes

"Nano" • Nanoscale - at the 1 -100 nm scale, roughly • Nanostructure - an object that has nanoscale features • Nanoscience - the properties of nanostructures and the underlying science • Nanotechnology - the techniques for making and characterizing nanostructures and putting them to use • Nanomanufacturing - methods for producing nanostructures in reliable and commercially viable ways

Nanotechnology: Why?

Example: Advancement of the i. Pod 10 GB 2001 20 GB 2002 40 GB 2004 80 GB 2006 160 GB 2007 Hard drive Magnetic data storage Uses nanotechnology!

Magnetic Data Storage A computer hard drive stores your data magnetically “Read” Head “Write” Head Signal S N N S 0 1 current Disk 0 0 1 direction of disk motion 1 0 _ _ “Bits” of information

Scaling Down to the Nanoscale Increases the amount of data stored on a fixed amount of “real estate” ! Now ~ 100 billion bits/in 2, future target more than 1 trillion bits/in 2 25 DVDs on a disk the size of a quarter, or all Library of Congress books on a 1 sq ft tile!

Why do we want to make things at the nanoscale? • To make better and new products: smaller, cheaper, faster and more effective. (Electronics, catalysts, water purification, solar cells, coatings, medical diagnostics & therapy, etc) • To introduce completely new physical phenomena to science, technology. (Quantum behavior and other effects. ) (More on why later)

Nanotechnology: How? • How to make nanostructures? • How to characterize and test them?

Making Nanostructures: Nanofabrication • Top down versus bottom up methods • Lithography • Deposition • Etching • Machining • Chemical • Self-Assembly

Nanostructures macroscale (3 D) object nanofilm, or nanolayer (2 D) height depth width nanowire, nanorod, or nanocylinder (1 D) nanoparticle, nanodot, quantum dot (0 D)

Nanofilms (making thin objects)

An example of a FILM: Oil on water A monolayer NANOFILM (single layer of molecules) ~1 nm thick Langmuir film This is an example of SELF-ASSEMBLY

Nanofilm by Thermal Evaporation Vaporization or sublimation of a heated material onto a substrate in a vacuum chamber sample QCM film vapor Au, Cr, Al, Ag, Cu, Si. O, others Pressure must be held low to prevent contamination! There are many other thin film manufacturing techniques vacuum ~10 -7 torr source resistive, e-beam, rf or laser heat source vacuum pump

Nanofilm by Electroplating V cathode Working Electrode (WE) I Cu. SO 4 dissolved in water anode Counter Electrode (CE) If using an inert Pt electrode: 2 H 2 O –> O 2 + 4 H+ + 4 e- "reduction" Cu 2+ + 2 e- –> Cu(0) "oxidation" Cu(0) –> Cu 2+ + 2 e-

Imaging Nanostructures Atomic Force Microscope (AFM)

"Optical Lever" for Profilometry laser cantilever .

"Optical Lever" for Profilometry laser Long light path and a short cantilever gives large amplification cantilever .

AFM Instrument Head Atomic Force Microscope AFM Cantilever Chip Laser Beam Path Cantilever Deflection

STM Image of Nickel Atoms

Lithography (controlling width and depth)

Lithography Mark Tuominen (Using a stencil or mask)

Photolithography for Deposition process recipe spin coating substrate apply spin bake spin on resist expose mask (reticle) exposed unexposed "scission" develop deposit liftoff narrow line

Lithography IBM Copper Wiring On a Computer Chip Patterned Several Times

Electron-Beam Lithography Electron Beam Polymer film Silicon crystal Nanoscopic Mask !

Self-Assembled Nanostructures and Lithography Based on Self-Assembly

Self Assembly

Diatoms sinancanan. net priweb. org

Gecko feet

Abalone

NANOFABRICATION BY SELF ASSEMBLY Diblock Copolymers Block “B” PS Block “A” PMMA ~10 nm Scale set by molecular size Ordered Phases 10% A 30% A 50% A 70% A 90% A

CORE CONCEPT FOR NANOFABRICATION Deposition Template (physical or electrochemical) Etching Mask Remove polymer block within cylinders (expose and develop) Nanoporous Membrane Versatile, self-assembling, nanoscale lithographic system

Application examples: Nanoelectronics

Computer Microprocessor "Heart of the computer" Does the "thinking"

Making Smaller An Example: Electronics-Microprocessors microscale nanoscale macroscale ibm. com

Electronics Keep On Getting Better Moore's "Law": Number of Transistors per Microprocessor Chip intel. com

Hard Disk Drives - a home for bits Hitachi

Improving Magnetic Data Storage Technology • The UMass Amherst Center for Hierarchical Manufacturing is working to improve this technology coil 1 bit Perpendicular Write Head Granular Media Y. Sonobe, et al. , JMMM (2006) Soft Magnetic Under. Layer (SUL) • CHM Goal: Make "perfect" media using self-assembled nano-templates • Also, making new designs for storage

Electrodeposited Nanowires in a Nanoporous Polymer Template (Mask) nanowires in a diblock copolymer template nanoporous template 1 x 1012 wires/in 2

Solar Cells Benefit: Sun is an unlimited source of electronic energy. Konarka

Electric Solar Cells Made from single-crystal silicon wafers (conventionally) Sunlight wires - cross-sectional view n-type silicon Voltage p-type silicon + - Current “load” + The load can be a lamp, an electric motor, a CD player, a toaster, etc

Nanostructured Solar Cells Sunlight Voltage More interface area - More power! Current “load” +

Nanotechnology R&D is interdisciplinary and impacts many applications • • • Physics Chemistry Biology Materials Science Polymer Science Electrical Engineering Chemical Engineering Mechanical Engineering Medicine And others • Electronics • Materials • Health/Biotech • Chemical • Environmental • Energy • Aerospace • Automotive • Security • Forest products • And others

Re: Your future My Advice to Students: • Pursue your interests • Ask questions • Be clever • Do! Thanks for visiting UMass and learning about nanotechnology!

Thanks from the UMass team! Thanks learning about nanotechnology!