Patent ID: 6910949

Claim:
A polishing head in an apparatus for chemically-mechanically polishing semiconductor wafers, the polishing head comprising: (a) a first side having at least a portion thereof operably connectable with a spindle on the apparatus, a downward force being applied exclusively by a mechanical force applied by the spindle to the semiconductor wafer during planarization; and (b) a second side opposite the first side, the second side having a substantially spherical cap shape comprising an outer region adapted to apply a first force onto a semiconductor wafer against a polishing pad, and an inner region adapted to apply a second force onto the semiconductor wafer against the polishing pad, the first force being greater than the second force, and wherein the first force and the second force cause the polishing pad to planarize the semiconductor wafer substantially uniformly; wherein the shape of the spherical cap distributes the downward mechanical force applied by the spindle as the first and second forces applied by the outer and inner regions of the spherical cap.