Feb 2007Stith1 Semiconductors Material, Components, and Manufacture Joseph Stith February 2007

Feb 2007Stith2 Outline Atom Electron Energy Levels Electrical properties of materials Doping Diodes Capacitors Transistors High-K dielectric / Metal Gate Flash Transistor Manufacturing Process Semiconductor Mfg History Possible Futures Intel Arizona Fabs

Feb 2007Stith3 Electron Energy Levels Electrons collect in various regions, often referred to as Energy Levels, shells, orbitals, etc. Drawn representatively as circles. Atoms seek stability: Full energy Levels: 2, 8, 8, … How many electrons does this Silicon atom seek? 4 Where does it get the additional electrons? Sharing outer shell electrons with other atoms that also want additional electrons, creating a bond. H 2 0 NaCl SiO 2

Feb 2007Stith4 Electrical Properties Insulator –No free electrons Conductor –free electrons Semi-Conductor –No free electrons –Insulator –But…

Feb 2007Stith5 Doping Increases conductivity N-Type (5 outer electrons) –Phosphorus or Arsenic P-Type (3 outer electrons) –Boron

Feb 2007Stith6 Diode P-Doped and N-Doped Regions Both regions are conductors Junction may not be a conductor ElectronsHoles Stable Covalent Electrons Depletion Region Negatively Biased HolesElectrons Holes & Electrons flowing Depletion Region Positively Biased

Feb 2007Stith7 Capacitor Two conductors separated by an insulator Plates charge, but no current flows through the capacitor. Once charged, there is an electrical field between the plates. Discharging one plate (e.g., attaching to ground) will still leave an electrical field. Electrical field will attract opposite particles in other plate

Feb 2007Stith8 Transistor With no gate charge, no current. –Two reversed diodes –One capacitor With a positive gate charge, a channel of negative ions form at the top of the P region, allowing current to flow.

Feb 2007Stith9 High-k + Metal Gate

Feb 2007Stith10 Flash Transistor Flash memory still uses MOS Transistors for control functions. Uses Flash transistors to store data Floating Gate surrounded by insulator

Feb 2007Stith11 Fab –Add material Implant Diffusion/Anneal –Heat raises energy of atoms to allow them to settle to a more stable location. Thin Films –Sputter, Oxidation, Chemical Vapor Deposition –Remove material Etch (chemical; acids): Wet (undercuts), Plasma (straight). Planar (mechanical) –Determining the pattern/Lithography Spin on a layer of Resist Expose to light through pattern (negative) Wash off the unexposed resist Add material (below) Wash off the exposed resist –Metrology (lot OOC, Tool OOC, Trending to OOC) C4 Sort Assembly/Test Manufacturing Process

Feb 2007Stith12 Manufacturing a Transistor /transistor/index.htmlhttp://micro.magnet.fsu.edu/electromag/java /transistor/index.html Gate Contact Drain Contact Source Contact 1. Layer SiO2 2. Apply Resist 3. Expose Resist 4. Remove unexposed 5. Etch SiO2 5. Remove exposed 6. Layer Polysilicon gate 7. Apply Resist 8. Expose Resist 9. Remove unexposed 10. Etch Polysilicon 11. Remove exposed 12. Dope Silicon 13. Add SiO2 14. Apply Resist 15. Expose Resist 16. Remove unexposed 17. Etch SiO2 18. Remove exposed 19. Layer Aluminum 20. Apply Resist 21. Expose Resist 22. Remove unexposed 23. Etch Aluminum 24. Remove exposed

Feb 2007Stith13 History

Feb 2007Stith14

Feb 2007Stith15 Possible Futures

Feb 2007Stith16 Possible Futures

Feb 2007Stith17 Future: Multi-Core - Polaris m/OverTheHorizon/? p=12http://blogs.zdnet.co m/OverTheHorizon/? p=12

Feb 2007Stith18 Intel Arizona Chandler Blvd –Offices –Assembly Test development area Ocotillo –F22 – 8” Fab - Closing Q1 2008, F32 will grow into the floorspace as it transitions to 32nm –F12 – 12” Fab – Running 65nm – Converted from 200mm - Converting to chipset fab. –F32 – 12” Fab – Startup 45nm - $3B - 184,000 square feet of clean room space

Feb 2007Stith19 Questions?

Feb 2007Stith20 Backup

Feb 2007Stith21 Further Info a/siliconcreature/sailboat.htmlhttp://micro.magnet.fsu.edu/electromag/jav a/siliconcreature/sailboat.html a/transistor/index.htmlhttp://micro.magnet.fsu.edu/electromag/jav a/transistor/index.html hysics/transistor/function/index.htmlhttp://nobelprize.org/educational_games/p hysics/transistor/function/index.html

Feb 2007Stith22 Contamination Class 1 clean room –10,000 times cleaner than an operating room. –1 particle (>.5 micron) per cubic foot of air. FOUPs –Allow for dirtier fabs Environment –72 degrees Fahrenheit –40% humidity –Positive air pressure Assembly/Test less strict Not Allowed: Gum, perfume, makeup, pencils, standard paper

Feb 2007Stith23 Electrons

Feb 2007Stith24

Feb 2007Stith25 t/Si/econ.htmlhttp:// t/Si/econ.html

Feb 2007Stith26 References html#tophttp:// html#top – mlhttp:// ml