CMP head structure with retaining ring

摘要

A CMP structure for CMP processing and a method of making a device using the same are presented. The apparatus comprises a polishing pad on a platen table; a head assembly for holding a wafer against the polishing pad, wherein the head assembly includes the retaining ring; a sensor for sensing the step height between the retaining ring and its membrane and a controller for adjusting the movement of the retaining ring based on the step height between the retaining ring and its membrane to ensure the step height remains at a fixed value as the retaining ring wears out.

主权项

1. A CMP apparatus comprising:
a polishing pad on a platen table; a head assembly, wherein the head assembly includes a retaining ring for holding a wafer in place on the polishing pad; a ring monitoring equipment configured for sensing and determining a step height between the retaining ring and a membrane of the retaining ring; a controller configured for calculating how much the retaining ring should be moved to ensure the step height between the retaining ring and the membrane remains at a fixed value; and a mechanism configured to move the retaining ring to ensure the step height remains at the fixed value as the retaining ring wears out.