Patent ID: 7018275

Claim:
A computer-implemented method of polishing, the method comprising: causing a carrier head to hold a wafer that includes a front side and a backside, the carrier head including one or more chambers and being operable, by adjusting pressure in at least one of the one or more chambers, to change a force applied to the backside of the wafer, a loading area on the backside of the wafer where the force is applied, or both the force and the loading area; polishing the front side of the wafer by holding the wafer against a polishing surface; obtaining thickness-related measurements of the wafer during polishing; calculating a thickness profile for the wafer based on the thickness-related measurements; comparing the calculated thickness profile to a target thickness profile; and defining, based on a result of the comparison, a recipe specifying a first set of pressure values for applying a first force to a first loading area, and a second set of pressure values for applying a second force to a second loading area, a first time interval during which the one or more chambers are pressurized in accordance with the first set of pressure values, and a second time interval during which the one or more chambers are pressurized in accordance with the second set of pressure values, each pressure value of a set representing the pressure at which a respective one of the one or more chambers is pressurized, wherein pressurizing the one or more chambers in accordance with the recipe during polishing results in a thickness profile that is more similar to the target profile than was the calculated thickness profile.