Introduction to Nanotechnology: What, Why and How

1. Introduction to Nanotechnology: What, Why and How bnl manchester Mark Tuominen, UMass, November 17, 2007

2. Nanotech: What?

3. Nanotechnology 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

4. Single Hair Width = 0.1 mm How small are nanostructures? = 100 micrometers = 100,000 nanometers ! 1 nanometer = one billionth (10-9) meter

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

6. From DOE

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

8. Nanotech: Why?

9. 20 GB 40 GB 10 GB 2001 2002 2004 Hard drive Magnetic data storage 80 GB 160 GB 2006 2007 Example: Advancement of the iPod Uses nanotechnology!

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

11. 25 DVDs on a disk the size of a quarter, or all Library of Congress books on a 1 sq ft tile! Scaling Down to the Nanoscale Increases the amount of data stored on a fixed amount of “real estate” ! Now ~ 100 billion bits/in2, future target more than 1 trillion bits/in2

12. 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.)

13. Nanotech: How? • How to make nanostructures? • How to characterize and test them?

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

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

16. Nanofilms(making thin objects)

17. An Early Nanotechnologist?

18. Excerpt from Letter of Benjamin Franklin to William Brownrigg (Nov. 7, 1773) ...At length being at Clapham, where there is, on the Common, a large Pond ... I fetched out a Cruet of Oil, and dropt a little of it on the Water. I saw it spread itself with surprising Swiftness upon the Surface ... the Oil tho' not more than a Tea Spoonful ... which spread amazingly, and extended itself gradually till it reached the Lee Side, making all that Quarter of the Pond, perhaps half an Acre, as smooth as a Looking Glass....

21. 2 cm3 = 20,000,000 cm2 ~ 2 cm3 V = 1 teaspoonful A = 0.5 acre ~ 2,000 m2 ... the Oil tho' not more than a Tea Spoonful ... ... perhaps half an Acre CHALLENGE: How thick was the film of oil? Volume = (Area)(Thickness) V = A t t = V/A = 0.0000001 cm = 1 x 10-7 cm = 1 x 10-9 m = 1 nanometer (nm) 20,000,000 cm2

22. An example of a FILM A monolayerNANOFILM (single layer of molecules) ~1 nm thick Langmuir film This is an example of SELF-ASSEMBLY

23. multiple dips - multiple layers Must control movable barrier to keep constant pressure Langmuir-Blodgett Film

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

25. Working Electrode (WE) Counter Electrode (CE) "oxidation" Cu(0) –> Cu2+ + 2e- Nanofilm by Electroplating I V cathode anode CuSO4 dissolved in water If using an inert Pt electrode: 2 H2O –> O2 + 4H+ + 4e- "reduction" Cu2+ + 2e- –> Cu(0)

26. BREAK

27. Imaging NanostructuresAtomic Force Microscope (AFM)

28. "Optical Lever" for Profilometry laser . cantilever

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

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

31. STM Image of Nickel Atoms

32. Lithography(controlling width and depth)

33. Lithography Mark Tuominen Mark Tuominen (Using a stencil or mask)

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

35. Lithography Patterned Several Times IBM Copper Wiring On a Computer Chip

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

37. Self-Assembled Nanostructuresand Lithography Based on Self-Assembly

38. Self Assembly

39. Diatoms sinancanan.net priweb.org

40. Gecko feet

41. Abalone

42. ~10 nm NANOFABRICATION BY SELF ASSEMBLY Diblock Copolymers Block “B” Block “A” PS PMMA Scale set by molecular size Ordered Phases 10% A 30% A 50% A 70% A 90% A

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

44. Application examples:Nanoelectronics

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

46. Making Small SmallerAn Example: Electronics-Microprocessors microscale nanoscale macroscale ibm.com

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

48. Hard Disk Drives - a home for bits Hitachi

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

50. Electrodeposited Nanowires in a Nanoporous Polymer Template (Mask) nanowires in a diblock copolymer template nanoporous template 1x1012 wires/in2