Wafer bow metrology system

Abstract

Aspects of the present disclosure provide a metrology system for measuring wafer bow of a wafer. For example, the metrology system can include a wafer support configured to position a wafer for wafer bow measurement, a first light source configured to illuminate a first side of the wafer during the wafer bow measurement, and a first pinhole mask disposed between the first light source and the wafer support. The first pinhole mask can include a plurality of first pinholes that are arranged to pass first light from the first light source and project onto the first side of the wafer a plurality of first dots that correspond to the first pinholes in the first pinhole mask. The metrology system can also include a first camera arranged to capture an image of the first dots from the first side of the wafer during the wafer bow measurement.

Dependencies are inferred from the claim text.