Z
Zak
Kai said:Also, remember that the strain is
usually quite minute, mechanically seen. But electrically, the strain
is measurable.
I'd think the strain must be huge, though over very short distances only.
If transistors would work better when the chip is mounted under slight
stress that would have been done long ago. Also an Si transistor would
make a handy strain gauge which they seem not to be.
I guess that the strain can be a few percent (see the SiGe lattice) -
which is a lot for a brittle material. But as it is in a very thin layer
and over short distances (areas of stretch and areas of compression
mixed) the overall mechanical effect is negligible.
Also, a thin layer will not store much mechanical energy which means
that cracks will not propagate. Right? Try to stretch something as
brottle as silicon my a few percent and you'll likely have a break
otherwise,
Thomas