Patent ID: 9685342
Date: 2017-06-20
CPC Classifications: B24B,H01L

Claim:
1. A wafer processing apparatus comprising: a rotatable platen having the capacity to support a polishing pad on a pad mounting surface of the rotatable platen; a drive assembly coupled to the rotatable platen and having the capacity to rotate the rotatable platen; a polishing head coupled to a head actuator, wherein the polishing head is disposed adjacent to and over a first portion of the pad mounting surface and wherein the polishing head is movable relative to the pad mounting surface by the head actuator; an optical sensor having a vision field including a second portion of the pad mounting surface, wherein the first portion and the second portion of the pad mounting surface are at least partially offset; an illumination source disposed adjacent to the pad mounting surface, wherein the illumination source is configured to illuminate the second portion of the pad mounting surface with a light pattern comprising a plurality of simultaneous lines separated by a predetermined spacing; and a control unit operatively connected to the drive assembly and the head actuator.