Extended height resolution in 3D Deflectometry

3D deflectometry is an optical slope sensing measurement technology. One realization of the deflectometry principle is the Fast Optical Scanning (FOS) deflectometer. The current Philips FOS configuration is able to measure flat and slightly curved surfaces with a width of 4" with a lateral resolution of 50 micron. Measuring in the slope domain with high lateral resolution a very high dynamic range in z – height can be achieved. In one measurement macro- and micro features of the surface under test can be captured. This extended height resolution showing several decades will be demonstrated using (patterned) semiconductor wafers as example.