News Industry to start move to 450mm wafers in 2012

Discussion in 'Article Discussion' started by Bindibadgi, 6 May 2008.

  1. Bindibadgi

    Bindibadgi Tired. Forever tired.

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  2. delsinboy

    delsinboy intermediate selfbuilder

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    what does this mean in practice? that was a bit technical for me.
     
  3. g3n3tiX

    g3n3tiX resident frenchy

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    The thing held in the picture will be bigger (i think) so that you can manufacture more chips at once. Combined with the fact that chips are getting finer detail (the famous 90 or 45 nm) and as such smaller size, you fit more into one.

    correct me if i'm wrong...
     
  4. Renze

    Renze New Member

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    I've always wondered why the wafers are round. Would it not be more efficient and produce less waste if they made them rectangular?
    Still, cheaper chips :D They'll hopefully be out buy the time I'm set for my next big upgrade
     
  5. iwog

    iwog Linux cursed

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    Its because they're grown not printed. Wiki link Basically its like making a candle where you start with some form of wick to which the silicon sticks to and then you pull it out as the crystals form the layers. And finally after you have you giant silicon candle you slice it and make the chip on it.
     
  6. theevilelephant

    theevilelephant New Member

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    the wafers are round because the silicon crystal the wafers a cut from is cylindrical (sp?). Back ontopic, woooo! cheaper chips here we come

    EDIT: doh beaten to it
     
  7. Renze

    Renze New Member

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    Thx guys, you learn something new everyday :D
     
  8. metarinka

    metarinka New Member

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    actually silicone crystals aren't round, which makes me wonder why they don't form them in the shape of the crystal ( believe the cross section is hexagonal but my books only list the crystal lattices of metals
     
  9. Dvs98SK

    Dvs98SK New Member

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    This is exactly right. I have seen them grown before and that is pretty much what is going on. The neck touches the melted silicon and starts to spin very slowly and rise at the same time. This could take a whole day to grow one rod depending on the materials and size used. I used to grow low temp oxide on Intel wafers before. My wife works on the 300mm SOI wafers right now. Not all the wafers are round either i have seen many different shapes and sizes. One was very square with all kinds of notches sticking out. That one was for NASA. I think they were for the stardust project.
     
  10. Xir

    Xir Well-Known Member

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    Standart 200 and 300mm (8" 12") wafers are round, smaller ones sometimes have one flat edge.
    While it is possible to cast square blocks of silicon, you end up with polysilicon, while semicon manufacturers need monosilicon.
    Poly beeing many crystals, mono beeing one big crystal.

    Poly square blocks are used for solar panels for instance.

    Monosilicon is usually made round, by the pulling process described above (only still slower)

    Having a round wafer has many disadvantages, for instance losses at the corners...layout a grid on a cirkle and count the "incomplete" squares on the sides.
    Then notice that when you increase the circle, the amount of incomplete squares compared to the amount of complete squares goes down. So bigger wafers means less incomplete squares (one square usually being a chip)

    The good thing about round wafers however is that it is easier to deposit and remove even layers on them. (nitride, oxide, copper...you wouldn't believe how many layers a chip is actually made of...most beeing removed again during production)

    Xir
     
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