Low Coherence Interferometry
<p>A Michelson Interferometer with a low coherence light source is used to determine distances: L2 is the beam path length from the light source LS to a surface or interface on the wafer w and back to the detector D. L1 is the beam path from LS to the reference mirror and back to D. If L1 = L2 interference is observed.</p>
Laser Scanning
<p>FSM uses patented Laser Scanning technology to measure the radius of curvature and bow of wafers. A laser beam is directed to the wafer. The beam is reflected at an angle that corresponds to the radius of curvature of the wafer.</p>
