Hello all,
i need to perform front and back photolitography.

On each side of a 4'' silicon wafer i need to realize geometries of size
10um. Geometries on the opposite wafer faces must be aligned with the best
possible accuracy.
Here we don't have the possibility to realize front-back photolitography
and so i plan to ask to some company to do the job for me.

Which is the best precision accuracy which can be obtained on the market ?

Best regards,
Andrea