APPLICATIONS

Wafer Geometry Inspector

Light-sectioning sensors

The profile of the wafer edge is measured using ARDAS-LS light-sectioning sensors. These sensors detect the light scattered from a laser line projected onto the surface of the sample. Constant regulation of the laser intensity automatically compensates for the varying reflection properties of the wafer surface.

The extremely short lengths of the light-sectioning line (approx. 1.5 mm) make it possible to obtain measuring accuracies of up to 1 µm.

As well as delivering extremely accurate measurements, the light-sectioning technique has another decisive advantage. Unlike the methods applied by traditional profile projection devices, this technique enables the edge profile to be measured in the notch area.