Patent ID: 8038508

Claim:
A wafer polishing apparatus, comprising: a polishing tape extending between two guide rollers, the polishing tape being substantially transparent and a first surface of the polishing tape contacting a surface of a wafer to be polished; a polishing head including a pusher pad, the pusher pad adapted to push the polishing tape against the surface of the wafer to be polished; a color image sensor adjacent to the polishing tape, the color image sensor being adapted to detect a color image of the polishing tape and to output a signal corresponding to the detected color image, and the color image sensor being on a second surface of the polishing tape, the second surface of the polishing tape being opposite the first surface of the polishing tape; and a controller connected to the color image sensor, the controller being adapted to receive the signal output from the color image sensor and to determine when a color of the color image detected by the color image sensor changes, a change in the color image indicating a polishing end point.