> I've heard that silicon wafers are not totally flat on the 1-0-0
> crystalline surface because a skew is introduced deliberately to
> prevent tunneling during ion implantation.

I believe this is totally bogus. Wafers are *tilted* and *rotated* during
implantation to reduce "channeling"; however, the surfaces should be flat to
the specification of wafer bow, total thickness variation (TTV), etc. and
oriented to (e.g., <100>) within that spec, typically < 1 degree.

On the other hand, wafers are often deliberately misoriented (i.e., ground to
an angle well off (several degrees) the axial direction for epitaxial growth.
Perhaps that's what you're thinking of.

- r.