摘要 |
An invention is disclosed for end point triggering in a chemical mechanical polishing process. A sensor array is positioned beneath a polishing belt having an end point window. The polishing belt is then rotated during the CMP process, and a transverse position of the end point window is determined based on a portion of the sensor array covered by a particular portion of the polishing belt. The particular portion of the polishing belt can be the end point window, a trigger slot, or a portion of the polishing belt covered by a reflective material. The sensor array can optionally be a charged coupled device (CCD), or a linear array of sensors. In operation, the positional information is determined based on which sensors are covered by the particular portion of the polishing belt. The positional information is then communicated to a belt steering system, which corrects the transverse position of the end point window based on which sensors are covered by the particular portion of the polishing belt.
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