Dogus University Electronics & Communications Engineering Intradepartmental Seminar June 01, 2006

1. Dogus University Electronics&Communications Engineering Intradepartmental SeminarJune 01, 2006 An Overview of Nanotechnology and its Applications in Electronics Indrit Myderrizi

2. Contents • Introduction • Survey of Nanotechnology Domains • Nano Fabrication Approaches • Nanostructures • Nano Electronics Architecture • Resources

3. Introduction • Nano– derived from an ancient Greek word meaning DWARF • 1 Nano = 10-9One billionth of something • 1nm = 10-9m One billionth of a meter • 10 hydrogen atoms shoulder to shoulder • Nanotechnology: • The art and science of manipulating and rearranging individual atoms and molecules to create useful materials, devices, and systems. • Research and technology development at the atomic, molecular or macromolecular levels, in the length scale of approximately 1 - 100 nanometer range.

4. Introduction

5. Electronics Communication Physics Agriculture Math Hospitality Chemistry Clothing Engineering Transportation Biotech Construction Materials Medical Medical Diagnostics Survey of Nanotechnology Domains • Nanotechnology is a new way of thinking and requires multidisciplinary activity, i.e. combinations of:biology, chemistry, computer science, engineering, material sciences, mathematics, medicine, physics Nano Technology

6. Survey of Nanotechnology Domains Illustrations of industries to benefit from nanoscale manufacturing technologies are: • Advanced materialsfor improved physical, chemical and biological properties. • - Such materials will include catalysts, nanostructured polymers, strong and lightweight nanoparticle, nanotube or nanofiber-reinforced polymer composites and metal alloys; nanoporous polymer and metal foams; nano-grained superhard coatings for machine tools, molds, superplastically deformable nanopowder-consolidated metals and ceramics for shape forming; smart materials with embedded conductive, piezoelectric, magnetostrictive, shape memory alloy or magnetorheological elements for color, texture, conductivity control and sensory or active behavior etc. • Electronics, information technologies and communications industries. • - Examples include: molecular or nanostructured switches, amplifiers and interconnects for analog/digital data processor and storage devices, including single-electron, spin and magneto-electronics and hybrid technologies; DNA computation platforms; liquid crystal and photonic flat/flexible panel displays, photonic crystals for optical signal processing in fiber communications; nanostructured wireless transmitter/receiver microdevices for local (RF) tag identification, or satellite localization (GPS) etc.

7. Survey of Nanotechnology Domains • Pharmaceutical, biochemical, food, power and environmental remediation industries. • - Examples are chemical/drug screening arrays; microbial, viral and toxic gas and food sensors for warfare defense and emission control; nanostructured catalysts for reactors; nanograined films, inks, paints, fire-retardant/resistant coatings etc; nanoparticle dispersions and aerosols; consolidated nanoparticle or nanostructured proton exchange membranes for fuel cells; filtration membranes for desalination and pollution control; nanostructured cells for flexible photovoltaics, artificial photosynthesis, new types of batteries etc. • Medical, health and safety industries. • - Examples are through drug/gene bioassay arrays forgenomics and proteomics research and clinical therapy; nanoparticle and nanospheremedication/gene vectors; nanostructured biomaterials for implants and prosthetics; implantable aid microdevices such as programmablemedication dispensers, pacemakers, pressure/glucose detectors etc; sterile surface catheters,surgical tools, and nanoparticle agent and sensor technologies for medical imaging;nanostructured biocompatible/biodegradable scaffolds for artificial tissue engineering andregenerative medicine etc.

8. Survey of Nanotechnology Domains • Aerospace, automotive and appliance industries. • - high strength/weight rationanostructured alloy and composite materials for fuselage, body and other structuralelements; highly resistive or ultra-low friction layers for thermal barrier coatings, bearingsurfaces etc. in jet, internal combustion, and hydraulic/pneumatic engines and elements;nanostructured microelectromechanical systems (MEMS and NEMS) such as accelerometerand gyroscopic sensors or fuel injection and supplementary restraint fluidic actuators,reconfigurable control surfaces, etc. • Service industries, including the users of nanomanufactured products. • - nanostructured and nanofabricated product design and prototyping companies; marketanalysis and marketing of such products; research and development laboratories andconsulting firms; intellectual property development and management services fornanomanufacturing technologies; related education at the technical school or college/university level; workforce training of professionals for nanomanufacturing industries;software development for product design, process simulation, modeling and control,continuous learning etc.

9. Nano Fabrication Approaches There are two approaches to making structures on the nanoscale: Top-down Method(present route) Creates nanostructures out of macrostructures by breaking down matter into more basic building blocks. Frequently uses chemical or thermal methods. Bottom-up Method(nano way) Building complex systems by combining simple atomic level components through self assembly of atoms or molecules into nanostructures

10. Nano Fabrication Approaches Top Physics Engineering Down Nanotechnology Lithographic Techniques Molecular Beam Epitaxy SPM Probes Nanoparticle Synthesis Supramolecular Chemistry – Aggregates CovalentChemistry

11. Nano Fabrication Approaches The electron beam initiates a chemical reaction in the organic material, either leading to fragmentation to smaller molecular components, which are soluble in some solvent (positive tone resist), or crosslinking to form an insoluble network (negative tone resist). 1 e e e e e e e e e e e e e e e “Organic” 1 Silicon 2 2 The unirradiated “organic” is removed with an organic solvent, leaving the cross-linked insoluble network pattern. Top Down Approach - Photolithography

12. Nano Fabrication Approaches A chemical etchant is employed to remove the exposed silica, and in so doing also etches the irradiated organic material, result in the pattern transfer to the silicon. 3 3 The pattern is then doped with appropriate materials to create an active pattern, i.e. will conduct electrons 4 4

13. Nano Fabrication Approaches Bottom Up - Selfassembly Step 1 Isolation of atoms or molecules: By using scanning tunneling microscope: By using atomic force microscope: Step 2 Assembly of loose atoms or molecules. Step 3 Re-bonding of atoms and molecules: Chemical synthesis

14. Nano Fabrication Approaches Self Assembly • Coordinated action of independent entities under distributed (i.e. non-central) control to produce a larger structure or to achieve a desired group effect • naturally occurs in biological (embryology) and chemical (supramolecular) systems -Nanoporous materials – templated nanosynthesis MCM-41diblock polymerzeolite

15. Nano Fabrication Approaches • Eventually the ‘top-down’ and ‘bottom-up’ approaches can both be combined into a single nanoelectronics manufacturing process. Such a hybrid method has the potential to lead to a more economical nano-manufacturing process. Photolithography + Self-Assembly Hybridization of these two approaches GA Institute of Technology

16. Nano Fabrication Approaches 10 nm 100 nm 0.1 mm 100 nm 35 nm 20 nm Microelectronic Component (photolithography) Bottom-up is meeting Top-Down Electron Beam Lithography can create structures of less than 10 nm. T. Desai, Univ. of Illinois at Chicago

17. Nanostructures • BuckyBalls • Carbon Nanotubes • Silicon Nanowires • Quantum Dots

18. Nanostructures Properties • Roundest and most symmetrical molecule known to man • Compressed – becomes stronger than diamond • Third major form of pure carbon • Heat resistance and electrical conductivity BuckyBalls – C60 Applications Polymers/reinforcements-Compounds-High quality diamond films for electronic chips and other devices-Insulator-Batteries and fuel cell electrodes-Strengthening and hardening of metals-Sensor applications-Surface hardening coatings-Catalysts-Biological/pharmaceuticals-Copiertoner-Organic chemistry building blocks-Chemical reagents C60 molecules & buckminsterfullereneMolecules made up of 60 carbon atoms arranged in a series of interlocking hexagons and pentagons C60 is actually a "truncated icosahedron", consisting of 12 pentagons and 20 hexagons.

19. Nanostructures Properties • Thermal/electrically conductive • Metallic and Semi-Conductive • 4 nm width (smaller diameter than DNA) • 100x’s stronger than steel 1/6 weight • can be single-walled (SWNT 1-3 nm) or multi-walled (MWNT 20-100 nm ). Carbon Nanotubes Applications Fillers in super-strong composite materials - Wires and components in nanoelectronic devices - Tips of scanning probe microscopes and in flat panel displays and gas sensors - As macromolecules should be ideal constituents of polymers, copolymers, polymer composites, and biological structures ♦Strong covalent bonding carbon molecules aligned in cylinder formation ♦Built by carbon vapor

20. Nanostructures Silicon Nanowires Properties • Precise diameter control of a few nm • Microns long • Selectively dope length to control electrical properties • Typical diameters of nanowires 50-100nm, although diameters as small as 3 nm are realized ♦Grown by chemical vapor deposition • Applications • Nanowires, tubes and particles are used in: • gates and switches in nano and microelectronics • tera-bits computer storage devices.

21. Nanostructures • Chemical vapor deposition involves a gas-phase chemical reaction occurring above a solid surface, which causes the deposition onto the surface • Principle of the synthesis is that nanoparticles of various transition metals act as catalysts to seed the growth of nanowires or nanotubes, using the feedstock gas as ingredients • Precursors are activated Nanotube/Nanowire Synthesis • Involves thermal activation or use of combustion flame (laser ablation and arc-discharge can also be used.)

22. Nanostructures Quantum Dot • Properties • Small metal or semiconductor box containing 2 electrons surrounded by an insulator with zero classical degrees of freedom moving out of the box • Electrons repel each other so that always take two farthest positions i.e (4,2) or (1,3). One of these configurations can be treated as 1 and other as 0 • A small voltage can be applied to switch between this two configurations • A good property of quantum dots : flow of energy from one end to other Applications • Quantum dots can be used to implement most of logic gates

23. Nano Electronics Architecture Nanotube Transistor Thesource/drain electrodes are typically formed by evaporatingmetal onto the top of the nanotube after it is deposited orgrown on top of a solid substrate, such as oxidized Si. the substrate was used as the gate. However,in order to allow individual addressing of SWNT FETs on awafer, and in order to reduce source-gate capacitance(important for high-speed), top-gates can be deposited if asuitable dielectric can be found which does not damage theSWNT. Carbon nanotube transistors: D ~ 1 nm

24. Single Electron Transistor Nano Electronics Architecture SET Transistor • A 3-terminal device with gate, source and drain • An SET switches the source-to-drain current on and off in response to small changes in the charge on the gate amounting to a single electron • SETs are based around an island, usually of metal and containing a million or more mobile electrons • Since the Coulomb interactions among electrons block electrons from tunneling onto the island at low bias voltages "Coulomb blockade" is observed • Increasing the gate voltage for a SET to a critical value suddenly allows current to flow from source to drain, but a further increase turns off the current just as suddenly. Additional increases repeat this on/off cycle. • In order to control the number of the electrons on the island, a metal gate electrode is placed • As the gate voltage increases further the number of electrons on the island stabilizes at a value one higher than before and yet no current flows.

25. Nano Electronics Architecture Logic Circuits from Carbon Nanotubes-Inverter

26. Nano Electronics Architecture Carbon Nanotube Switches Core Shell Nanowires Gated by Nanotubes or Nanowires FET Diode

27. Resources [1] Goldhaber-Gordon, D., Montemerlo, J. S., Love, J. C., Opiteck, G. J., Ellenbogen, J. C., “Overview of Nanoelectronic Devices”, MITRE Corp, The proceedings ofIEEE, April 1997 [2] Burke, P.J., Yu, Z., Li, S., Rutherglen, C., " Nanotube Technology for Microwave Applications", Integrated Nanosystems Research Facility, Department of Electrical Engineering and Computer Science, University of California, Irvine [3] DeHon, A., "Array-Based Architecture for FET-Based, Nanoscale Electronics", IEEE Transactions on Nanotechnology, vol. 2, no. 1, March 2003 [4] Joshi,J., "Nanotechnology. Machines, Tools & Architecture", www.tinman.cs.gsu.edu/~mpandya1/cs8530/jaimini/ [5] Wayner, D. D. M., " National Institute for Nanotechnology, Update and Status", www.thecis.ca/recordevents/wayner [6] Aourag, H., "Nanotechnology: A big issue in a small world", URMER University of Tlemcen