Patent attributes
Disclosed is a carrier head of a chemical mechanical polishing apparatus for planarizing a semiconductor wafer. An adjustment chamber is provided in a space section formed between a membrane lower holder and a membrane upper holder of a wafer support assembly. Pressure applied to the adjustment chamber is transferred to a rear surface of a membrane during a polishing process through a perforated hole formed at a center of the membrane lower holder. A center portion of the membrane is connected to a vacuum pipe by passing through a hole of the membrane lower holder and the adjustment chamber. Vacuum pressure is directly applied to a wafer so that the wafer is easily attached to the carrier head at lower pressure. Pressure is evenly distributed over the whole area of the wafer so that the wafer is evenly polished.
