Chemical mechanical polishing method

A chemical mechanical polishing method, comprising:

• polishing a wafer on a polishing surface of a polishing pad;
• conditioning the polishing surface with a pad conditioner, wherein the pad conditioner is operable to apply a downward force according to a predetermined downward force stored in a controller to condition the polishing surface at a conditioning position, and move from the conditioning position to a home position away from the polishing pad after the conditioning the polishing surface;
• providing a measurement tool separate from the pad conditioner and measuring the downward force actually applied by the pad conditioner with the measurement tool after the conditioning, wherein the measurement tool is disposed relative to the pad conditioner at the home position;
• comparing the downward force measured by the measurement tool and the predetermined downward force with the controller to determine whether a difference between the downward force measured by the measurement tool and the predetermined downward force exceeds a range of acceptable values;
• and
• calibrating the downward force actually applied by the pad conditioner with the controller when the difference exceeds the range of acceptable values.

A chemical mechanical polishing method, comprising:

• polishing a wafer on a polishing surface of a polishing pad with a polishing head, wherein the polishing head holds the wafer in contact with the polishing surface during the polishing;
• conditioning the polishing surface with a pad conditioner after the polishing, wherein the pad conditioner is operable to apply a downward force according to a predetermined downward force stored in a controller to condition the polishing surface;
• after the conditioning, measuring the downward force actually applied by the pad conditioner with a measurement tool when the pad conditioner rests at a home position away from the polishing pad rather than over the polishing surface;
• comparing the downward force measured by the measurement tool and the predetermined downward force with the controller to determine whether a difference between the downward force measured by the measurement tool and the predetermined downward force exceeds a range of acceptable values;
• and
• calibrating the downward force actually applied by the pad conditioner with the controller when the difference exceeds the range of acceptable values.