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Silicon + ir

  1. Apr 28, 2009 #1
    hi everyone...

    i have got a general doubt....I have heard that silicon is transparent to
    infrared...so does that mean that any IR wave entering silicon comes out of it without any change??? Is silicon 100% transparent to IR? does the transparency depend on temperature or any other parametre?

    Can anyone give me some reference material, suggest some books or some links where i can get data about silicon transparency?

    please hep me...
    thanks in advance...
  2. jcsd
  3. Apr 29, 2009 #2


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    Well, it's about the same as, for instance, glass for optical wavelengths. It looks more or less transparent, and the transmission is in the high 90s, but there is some (small) absorption and some refraction and a small bit of reflection. There's a mask aligner in the place I work at that uses backside IR illumination so you can align masks to features already present on the silicon. Haven't used it myself, however.

    Here's a paper from Virginia Semiconductor (they make custom silicon)--this is targeted mostly to researchers, and it may be difficult to understand without some optics background:
    http://www.virginiasemi.com/pdf/Optical%20Properties%20of%20Silicon71502.pdf [Broken]
    Last edited by a moderator: May 4, 2017
  4. Apr 29, 2009 #3

    Andy Resnick

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    Last edited by a moderator: May 4, 2017
  5. Apr 29, 2009 #4
    Hi matlabdude,
    thanku very much for the response and the reference u gave....taking a quick look at the data u gave and the data andy resnick gave...the maximum transmission seems jus below 60%. however u pointed out tat transmission is at high 90's ....
    anyway thanyou for the data you gave....
  6. Apr 29, 2009 #5
    HI andy resnick,
    thanku for the valuable links...
  7. Apr 29, 2009 #6


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    High 90s is visible light through a thin piece of glass (I was laying down the groundwork in case you didn't have any background)
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