Presentation delivered by Dr. Grace Xing at the Culver Academies campus on her research and the importance of AFM and SEM imaging techniques.

1. 1 Nano Materials and Nano Scale Imaging Prof. Grace Xing Dr. Chuanxin Lian Electrical Engineering Department University of Notre Dame

2. 2 Outline Introduction to Xing Group and Research Discussion of Optics History Ranges of Visual Resolution Scanning Electron Microscopy (SEM) Fundamentals Operation Scheme Atomic Force Microscopy (AFM) Scanning Tunneling Microscopy (STM) Demonstration of AFM imaging

3. Xing Group Members 3

4. Graphene Group 4

5. Nitride Group 5

6. Our Labs 6 AFM

7. III-V Nitride 7 III-V nitride Diamond Rock Salt

9. Energy bands in solid  different conductivity Real space coordinates

10. Let us understand “Scale” and “Electronics” 10

11. The Scale of Our Existence The universe covers about 40 orders-of-magnitude (factors of 10) in size. We sit somewhere in the middle!

12. The Size of the Familiar 10 meters 1 meter (Photos from CERN and Scientific American)

13. The Size of the Familiar 1000 meters 100 meters

14. The Size of the Familiar 100,000 meters 105 meters 10,000 meters 104 meters

15. The Not-So Familiar 107 meters 106 meters

16. The Not-So Familiar 109 meters Orbit of the moon 108 meters

17. The Not-So Familiar 1011 meters Orbit of Venus and Mars 1010 meters

18. The Not-So Familiar 1013 meters Solar System 1012 meters Inner Solar System

19. The Not-So Familiar 1014 meters

20. The Fantastic 1021 meters 1020 meters

21. The Fantastic 1023 meters Local Group 1022 meters Magellanic Clouds

22. The Fantastic 1026 meters

23. Now Heading Down in Size 0.1 meters 1 meter

24. Small but Gross! 0.001 meters 10-3 meters 0.01 meters 10-2 meters

25. Small but Gross! 0.00001 meters 10-5 meters 0.0001 meters 10-4 meters

26. 10-7 meters 10-6 meters

27. 10-9 meters DNA Molecules 10-8 meters DNA Strand

28. 10-14 meters 10-13 meters Carbon Nucleus Carbon Atom

29. 10-16 meters ? 10-15 meters Proton Quarks

30. Small but Familiar CMOS Integrated Circuit 10-5 meters

31. Do You Own a Computer? Oxford English Dictionary, 1933

32. ENIAC 17,500 Tubes 174 kW! How Fast? 5,000 additions per second!!

33. What’s a Bug? Aiken Relay Calculator, 1947

34. The First Transistor This gets you a Nobel Prize!

35. First Integrated Circuit Jack Kilby, Texas Instruments, 1959 This also gets you a Nobel Prize!

36. Planar Integrated Circuits Robert Noyce, 1961 0.6 Inches In 1968 Robert Noyce, Gordon Moore and Authur Rock found what company? Intel

37. Silicon Wafers Today 300 mm Si wafer

38. ICs are Small (Sort-of) 1983 1968

39. Cleanrooms – The tiniest dust particle is a boulder

40. Intel 45 nm Penryn Dual-Core 107 mm2 400 million transistors 45 nm Process Technology 65 W, ~1V (High performance chips up to 178 W, 0.7 V)

41. Notre Dame Class Project Notre Dame music chip - 7k transistors, 7 mm die

42. Molecular Motors Protein “propeller” and F1-ATPase “motor” Single (big) molecule

43. Summary on scale and electronics Electronics has come a long way very quickly. Electronic devices are everywhere. Nanotechnology promises to continue this progress into the future. You are the ones to do it! Enjoy!!

44. 44 source How do we see an object? target detector …and often you’ll need a lens

45. 45 Requirements of Vision The light that reaches the eye must have a color between red (760nm) and blue (400nm) – or a mixture of these colors The light that reaches the eye must be sufficiently bright – usually requires a sufficiently bright source www.uvabcs.com/uvlight-typical.php , August 31, 2009 UV UV UV C B A visible light infrared 760 wavelength in nm 3000 290 320 760 400

46. 46 Object and Source Matching

48. But our eyes can’t detect x-rays - 0.1nm light - (5000 times smaller wavelength than we can see)

49. Options

50. Use x-rays and detector (to replace the eye)

51. Use particles (e.g. electrons) and detector

52. Electrons of the appropriate wavelength are easier to produce and direct than light – Scanning Electron Microscope (SEM)

53. Alternate imaging techniques

54. Atomic Force Microscope (AFM)

56. 49 Let’s bounce something else at the surface! e- e- e- e- e- e- e- e- e- e- e- Basic Idea? Animal sight and traditional microscopes collect deflected light Some are “reflected” Some are absorbed

57. 50 Electron Beam Column Beam created from heated filament Beam travels through a vacuum Electro-magnetic fields act as lenses Electron beam hits the sample in a precise location Scattered and “secondary” electrons are detected Beam scans back and forth http://bioweb.usu.edu/emlab/TEM-SEM%20Teaching/How%20SEM%20works.html

58. 51 Electrons Hit Surface and Detection Primary electrons come from the beam Some scatter back, others dislodge electrons http://www4.nau.edu/microanalysis/Microprobe-SEM/Signals.html

59. 52 Example Images http://gsc.nrcan.gc.ca/labs/ebeam/sem_gallery_e.php

60. 53 Atomic Force Microscope Valerie Goss

61. 54 What is the AFM? An analogue! We can sense with our hands by touching.

62. 55 AFM cantilever and AFM tips www.veeco.com

63. 56 The powerful, versatile AFM Resolutions: X and Y 2 -10 nm Z 0.05 nm Microstructure of solids: CD, glass beads, circuits Biological samples: skin cross section, viruses, bacteria, blood, DNA and RNA ~30 um scan www.nanotech-now.com/.../antonio-siber.htm Aug 27, 2009

64. ND Logo “written” by AFM tip 57 Anodic oxidation

65. 58 Scanning Tunneling Microscope Rebecca Quardokus

66. 59 Scanning Tunneling Microscopy (STM) Electrons tunnel! With a higher probability than cars STM measures the current created by tunneling electrons Images courtesy of http://www.ieap.uni-kiel.de and www.renault.com

67. 60 Scanning Tunneling Microscopy (STM) C60 “Bucky Balls” Each C60 diameter is ~ 10Å 1 Å = 1x 10-10 m Image courtesy of http://nano.tm.agilent.com

68. 61 Scanning Tunneling Microscopy (STM) Xenon on Nickel Individual atoms? That’s small! Iron on Copper Images courtesy of http://www.almaden.ibm.com