| 摘要 |
The invention provides a polishing machine and a three-chambered polishing head structure and method that improves the polishing uniformity of a substrate across the entire surface of the substrate, particularly near the edge of the substrate that is particularly beneficial to improve the uniformity of semiconductor wafers during Chemical Mechanical Polishing (CMP). In one aspect, the invention provides a method of controlling the polishing pressure over annular regions of the substrate, such as a wafer, in a semiconductor wafer polishing machine. The method includes controlling a first pressure exerted on the wafer against a polishing pad to affect the material removed from the wafer; controlling a second pressure exerted on a retaining ring, disposed concentric with the wafer, directly against the polishing pad, to affect the manner in which the polishing pad contacts the wafer at a peripheral edge of the wafer; and controlling a third pressure exerted within a predetermined annular region proximate an inner annular region of the retaining ring and an outer annular edge of the wafer to affect a change to the first and second pressure only proximate the annular region. Each of the first, second, and third pressures being independently controllable of the other pressures.
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