Is Silicon Transparent to Infrared Light?

[rr00053]

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...

 

[MATLABdude]

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

 

[Andy Resnick]

Transmission for Si:
http://www.almazoptics.com/Si.htm

Compare this to, for example ZnSe:
http://www.korth.de/eng/503728952d091450d/503728952d0c26651.htm

Or som other materials:
http://infrared.als.lbl.gov/content/web-links/58-irwindows

 

[rr00053]

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...

 

[rr00053]

HI andy resnick,
thanku for the valuable links...

 

[MATLABdude]

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...

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)