OT? Infrared control and such

[Martin Czech]

Yes, I was very sloppy.

If you view a chip under microscope light and forget to switch the ligth
off during measurements, you can get all kinds of weird effects.
Of course , digital static circuits are unaffected, but dynamic or
analog circuitry could fail. It is simple white light (incandescent),
broad band, as you say.

Did you know that all chips emit IR light? You can learn a lot about
internal currents, leakage currents and so on if the light of a silicon
chip is fed into a IR camera.

Of course, this is more to find defects...

m.c.

 
:::This isn't quite right. Si is an indirect bandgap semiconductor and cannot
:::be used as an LED (or laser). As a detector it operates throughout both the
:::visible and near IR, ca 350-1100 nm. For LED's, compound semiconductors are
:::used, both for visible and NIR.
:::
:::  Ian
:::
:::>
:::> :::There are (roughly speaking) infrared equivalents of LED/LDR's at work
:::here,
:::> :::yes?
:::>
:::> Yep, but in contrast to CdS LDRs infrared sending/detecting uses
:::monolithic
:::> silicon. It is the "natural mode" of Si to deal with infrared.
:::> Visible light will need compound semiconductors.
:::>
:::