Hi everyone,

I will do p+ doping into selected areas on one side of wafer.
the wafer is double side-polished and both of the sides are
plain. I will need to do backside (using IR) alignment with
the p+ doped side facing down. Since I am aware of that p+
doped regions block the IR light signficantly, I just wonder
whether or not I would be able to distinguish undoped regions
from doped regions using IR light. The target depth for p+
doping is 5-6 microns.
If anybody has done the same or similar process, I will be
appreciate your comments and suggestions,


Levent Yobas