Since Si is a cubic cristal, and the cubic lattice remains cubic with
temperature variation, the TCE of Si must be anizotropic. Any anisotropy
would result in lattice deformation, which is not the case for stress-free
bulk crystal....
Mike

> -----Original Message-----
> From: Shay Kaplan [SMTP:[email protected]]
>
>
> Hello Harry,
> I have looked at this for a long time and could never find data to support
> difference in TCE for the different orinetiations. Manufacturers I asked
> said either that there is no difference or that they don't know.
> Shay
>
> D H Grantham wrote:
>
> > Hi, Ken:  If you've not already gotten an answer to your question
> regarding coefficient of expansion, I can tell you that there is a
> difference.  {111} shows isotropic behavior in the plane of the wafer, as
> I recall.  I don't have the numbers off the top of my head but can tell
> you that there are handbook answers regarding these and and similar
> properties.  I do not recall that resistivity makes a big difference.
> >
>