Patent ID: 7799166

Claim:
A system for exposing an edge of a wafer, said system comprising: means for holding and rotating the wafer; a single wafer edge expose unit which comprises a light source and a sensor which is incorporated into the wafer edge expose unit, wherein said light source comprises an ultraviolet light source for emitting ultraviolet light and exposing the edge of the wafer, said system further comprising a secondary light source spaced away from the single wafer edge expose unit and configured to emit light toward the light source of the wafer edge expose unit, wherein the sensor of the wafer edge expose unit is configured to sense, from within the ultraviolet light, the light emitted from the secondary light source through the ultraviolet light, and the system is configured to use the ultraviolet light to expose the edge of the wafer and use the sensor and the secondary light source to sense the edge of the wafer; and means for moving the single wafer edge expose unit depending on what the sensor senses.