Lecture-18 - Scott Thompson - EC by fjhuangjun

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Lecture : 18 Flash: What Carbon
Nanotubes Would Need to Beat




       S. E. Thompson Fall 2004
Considerations:                                                              2


Nanotechnology as Memory
•   Mung Chen, Manager Technology Strategy, Intel Corporation

•   “Memory is viewed as a easier interim target for nanotech than logic.”
•   “Memory only needs to switch. Logic needs to switch and "gain.”
•   “It's not too difficult to demo anything as a potential memory device.
    But memory has never been an easy business because nobody wants
    to pay any extra for bits, whether it is called "nano memory" or not.
    Memory production cost depends mainly on 2 things: 1. cell size; 2.
    mask count.”
•   “Can a "bottom-up" scheme be developed. Any memory scheme based
    on "top-down" will have the same limitations as conventional memory.
    Smaller cell or few mask (e.g. vs.NAND) will be challenging, not to
    mention what it takes to develop applications/markets, and eventually
    sell for nano-dollars per bit.”




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Potential Applications for Carbon Nanotubes


•   Interconnect
•   Field emission
•   STM/AFM tip
•   Memory
    – Flash non-volatile memory
• Sensors
• Transistor




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Memory Overview
     From http://www.wordiq.com and see for more info




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OUTLINE

  This Lecture
  • Products
  • How Flash works
  • NAND and NOR Flash
  Next Lectures
  • Other non-volatile memory




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NAND Flash Non-Volatile Flash Cards


Compact Flash       SmartMedia
                                    Memory Stick




                                        MultiMedia and Secure
                                             Digital Cards



         Memory cards various standards:


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Sony’s Memory Stick




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Inside the Compact Flash Card
   Top Side                        Bottom Side




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References




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General Flash Concept




                                Two States
                                (-)(-)(-)
                                No charge
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Wordline / Connects Bit to Bitline




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Various Flash Memory Cells




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Stored Charge: VT Shift




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AMD’s MirrorBit




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NAND VS NOR Flash




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Various Flash Memory Technologies




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NAND vs. NOR




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NAND vs NOR Layout




      Note simplicity of NAND cell vs CNT memory
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Best Cell Size if Use Tops Down
F = printable feature size
Area = 4F2




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NAND Flash Program/Erase




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NOR Flash Erase Method




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NOR Flash Endurance




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NAND Flash Endurance




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S. E. Thompson EEL 6935

								
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