Wafer protection method
AssigneeCalitech Co., Ltd.
InventorChin-Ting Kuo
Life of this patent
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Abstract
The present invention discloses a method and a system of wafer protection of a chemical mechanical process. It takes an image on the polishing pad, and analyzes and identifies the image. If the wafer is out of a polishing head, a signal will be sent to the chemical mechanical polishing station to respond adequately. Otherwise, repeats the image obtaining and its following analysis and identification. The present invention can avoid broken wafers and reduce the station recovery time. Hence, it can increase the up time and the throughput of the station.
Claims6
In a method for protecting a wafer in a chemical mechanical polishing station for being pressed to contact a polishing pad of said chemical mechanical polishing station by a polishing head carried by a robot arm, the improvement of said method comprising the steps of:
- capturing images of a region located in a rotating path in front of said wafer by a camera;
- analyzing said images to identify a wafer located on said polishing pad if said image shows that said robot arm is above said polishing pad;
- and
- stopping said chemical mechanical polishing station if a brightness level of said image is higher than a predetermined threshold representing said wafer is away from the press of said polishing head.
Dependencies are inferred from the claim text.