Methods and apparatus for detecting a substrate notch or flat

摘要

In a first aspect, a first apparatus is provided. The first apparatus includes a through-beam sensor coupled to a scrubber and adapted to detect a notch or flat of a substrate in the scrubber during processing. The through-beam sensor has (1) an emitter facing a first major surface of a substrate in the scrubber and adapted to transmit a beam toward an edge of the first major surface; and (2) a receiver facing a second major surface of the substrate and adapted to receive the beam transmitted from the emitter when the edge of the substrate does not obstruct the beam. Numerous other aspects are provided.