Patent ID: 7813542
Filing Date: 2010-10-12
Classification: G06T,H01L,Y10S

Abstract:
1. A wafer aligning apparatus comprising: a laser sensor adapted to generate a trigger signal; an illuminator adapted to illuminate a wafer being transferred by a transfer robot from a cassette disposed in a load lock chamber to a transfer chamber, wherein the illuminator is adapted to illuminate the wafer in accordance with the trigger signal; a Charge-Coupled Device (CCD) camera adapted to take an image of the wafer in accordance with the trigger signal and adapted to convert the image into digital signals; a signal processing unit adapted to calculate a center alignment correction value for the wafer by comparing the digital signals to a master image stored in the signal processing unit; and, a robot controller adapted to receive the center alignment correction value from the signal processing unit and control movement of a transfer robot in accordance with the center alignment correction value, wherein the laser sensor is adapted to generate the trigger signal in accordance with a substantial change in an amount of reflected light detected by the laser sensor, and the substantial change in the amount of reflected light detected by the laser sensor occurs after a boundary between a robot arm of the transfer robot and a coupler of the transfer robot passes under the laser sensor, wherein the robot arm has a first color and the coupler has a second color different than the first color.