Patent attributes
A system and method for prealigning a substrate. One embodiment provides a rotor configured to rotate a carrier around a rotation axis in response to a rotation signal. The carrier includes a main surface substantially perpendicular to the rotation axis. The substrate is disposable on the carrier. The substrate includes a main surface and a mark such that an orientation of the substrate with respect to the rotation axis is detectable. An electromagnetic radiation source is configured to illuminate the main surface of the substrate with electromagnetic radiation. An optical/electrical converter is responsive to the electromagnetic radiation reflected back from the main surface, detecting the mark of the substrate and providing a sensing signal. A controller is configured to receive the sensing signal and providing the rotation signal.
