1. DILBERT

8. Summary of Project to Date
Did research and learned about several communication devices – cellular phones, Bluetooth/Wi-Fi, and RFID
Received silicon wafer to be used as base for antennas – could use other substrates if equipment was available
Received a traveler defining the steps necessary to fabricate your antenna
Cleaned silicon wafers to provide a contamination free surface
Grew SiO2 (silicon dioxide) to provide an insulating dielectric surface
Determined your application, either cellular, Bluetooth/Wi-Fi, or RFID
Determined how to find the correct length for the antenna based on the application
Using a decision matrix determined the conductor to be used to fabricate the antenna
This week will deposit conductor of choice

9. Thin Film Deposition Conductors are deposited using a vacuum chamber
The vacuum chamber reduces the atmosphere to high vacuum levels (no atmosphere)
This reduces contaminating the films, provides a non-contaminating environment free of oxygen, water vapor, etc. and allows materials to melt at lower temperatures.

10. Thin Film Deposition
Thin film deposition tools are very complex due to the need to create high vacuum levels.
Vacuum levels of 5x10-7 torr and better are typical. Sea level atmospheric pressure is about 740 torr or 7.4x102
Because of their complexity, vacuum chambers are very expensive.

11. Thin Film Deposition
To achieve high vacuum levels, several types of vacuum pumps are used.
Mid level vacuum levels (2x10-3 torr) are reached with rotary vane vacuum pumps. These pumps are also know as mechanical or roughing vacuum pumps
High level vacuum levels are reached using
Diffusion vacuum pumps – requires liquid nitrogen to prevent oil contamination
Turbomolecular pumps – like a small jet engine, clean and fast, good for processes that require the introduction of a process gas. Because of the high speed vanes, subject to catastrophic failure
Cryogenic vacuum pumps – uses low temperature (10oK) – also clean and fast pumping but requires regeneration periodically which is time consuming

12. Thin film deposition tools in the ECE Microelectronics Clean Room
Cooke-thermal deposition
CVC 601-sputter deposition
CHA Mark 50 e-beam deposition
Varian 3125 e-beam deposition

13. Conductor Deposition
The Cooke thermal evaporator is not currently used.
The CVC sputter tool is used only for aluminum depositions. Only an aluminum target is available.
The Varian 3125 and CHA Mark 50 e-beam deposition tools are used for all other conductors, Cu, Au, Ag, Cr, Ni
An e-beam evaporates material, it get the material so hot it becomes a gas and evaporates. It then travels in a straight line, because it is under vacuum, until it condenses when it strikes a colder surface

15. With sputtering, an Argon plasma is formed, causing argon ions to strike a metal target and knock loose material. Because an electric field is created, material is deposited on the substrate
Argon plasma – ionized argon in an electric field
Material target
Substrate to be coated

16. E-beam Evaporation uses a high energy electron beam to vaporize (change from a solid to vapor) materials, especially metals

18. Overall view of the Varian 3125 vacuum chamber
Overall view of the Varian 3125 vacuum chamber. This tool deposits thin films using e-beam evaporation

19. Portion of Varian 3125 control rack

20. Varian 3125 quartz heater controller, shutter controller and planetary rotation controller
E-beam shutter controller
Planetary (wafer holder) rotation controller

21. Electron beam power supply
Electron beam can be steered by magnetic fields
Typically 6-8KV are required to form the electron beam

22. Cryopump temperature-must be below 15oK

23. Varian 3125 ion gauge controller and deposition controller

24. Varian 3125 view of open chamber
Wafer planetary – can rotate or stay stationary. Can be removed for loading

25. Varian 3125 4-pocket e-beam crucible

26. With an e-beam (electron beam) evaporator the material is heated to a vapor (gas) and then condenses on cooler surfaces
Substrates (wafers) sit at the top of the chamber
Electron beam is formed and strikes the metal crucible
Molten material hot enough to vaporize (become a gas)

27. Varian 3125 wafer planetary
Wafer planetary for Varian 3125

28. Wafers are held down by spring clips
Varian 3125
Wafers are held down by spring clips

29. Varian 3126 Quartz Heaters

30. Varian 3125 door showing glasds slide holder
Glass slide must be replaced before each run

31. Overall view of the CHA Mark 50 vacuum chamber
Overall view of the CHA Mark 50 vacuum chamber. This tool deposits thin films using e-beam evaporation

32. Inside of CHA Mark 50 chamber showing wafer platen – can not be removed from the chamber

33. CHA Mark 50 wafer adapter ring
Adapter ring for 4”/100mm wafer
Adapter rings are available for 2”, 3” and 4” wafers

34. CHA Mark 50 4-pocket e-beam crucible
Four different materials are available to do sequential evaporations

35. CHA Mark 50 crucible materials and chamber temperature monitor
Materials currently inside the 4 pocket crucible are shown with their pocket number
Pocket is chosen using this indexer

36. CHA Mark 50 crystal oscillators for evaporation material thickness measurement

37. New glass slides must be used for each evaporation

38. CHA Mark 50 cryo-pump control
Cryogenic pump temperature – should be less than 15oK

39. CHA Mark 50 vacuum gauge controller
Vacuum chamber pressure of 7.5 x 10-7 torr

40. CHA Mark 50 E-beam power supply and controller
High voltage switch and current control
Power supply main on/off switch
Power supply is interlocked to prevent activation if vacuum pressure, cooling water, and zero current conditions are not met

41. Crucible being heated by an electron beam
E-beam evaporation
Crucible being heated by an electron beam

42. Overall view of the CVC vacuum chamber
Overall view of the CVC vacuum chamber. This tool deposits thin films using “sputtering”

44. CVC sputter tool with chamber lid open
Wafers are loaded into position

45. Looking into the CVC sputter tool chamber, showing the 8” aluminum target

46. CVC sputter tool control racks
Ion gauge

47. Argon MFC – 30 sccm flow typical
Cryo pump temperature – must be below 16oK

48. CVC sputter tool DC power supply for aluminum target
DC Voltage about 4KV
DC current 0.5 to 1.0 A

49. CVC sputter tool view port

50. View of argon sputter plasma in CVC sputter tool

51. View of argon plasma in AJA sputter tool
Sputter target
Shutter
Substrate (wafer) stage
Wafer stage can rotate and heat

52. Homework Assignment Due next class meeting
Review “Mask design steps” from web site
Read “Designing Antennas for Cellular Telephones” from web site.
Find “AutoCad” on Mosaic – listed under Mechanical Engineering as AutoCad 2006
Become familiar with AutoCad. There is a tutorial on my web site
Begin preliminary dimension sketches for your antenna design
Maximum size 20mmx20mm
Minimum size 5mmx5mm
Line width – 1mm
Spacing between lines – 1mm or greater
No sharp corners
Must be able to fit inside a box to allow cutting into individual antenna
Length must match your design length
Can be any design – be creative
Dimension drawing of your design is required

54. Simple spiral design

55. Cingular Logo design

56. XBOX design Note-DO NOT USE WHITE ON BLACBACKGROUND

57. Football Design- DO NOT USE WHITE ON DARK BACKGROUND

58. UNC-Charlotte Crown design

59. Dimensions not in a contrasting color