Hello,

I've kind of gotten myself in a bind and was wondering if anyone out there
had an idea of how I could get myself out of it.

The situation is this:  I've bonded single-side polished <100> wafers
together with an oxide in between.  The wafers are between 500 and 538
microns thick and the oxide is about 0.8 microns.

The problem is: the company I've asked to polish down the top wafer needs
to know how thick (within a micron) the wafers are.

I would prefer not to damage the wafers.  They are annealed, btw, so
separating and rebonding is not an option.  The ideas I've had so far
require some damage.  A KOH etch down to the oxide with subsequent measure
of the base area of the resulting triangular hole might be accurate
enough. A profilometer would require cutting the wafer and the Dektak I
have can only go 100 microns.

Any ideas?  Thanks in advance.

Mike


Michael H. Beggans
New Jersey Institute of Technology (NJIT)
[email protected]
973-642-7738 voice
973-596-5794 fax