Patent ID: 7731572

Claim:
A CMP head, comprising: a membrane support substantially being disk-shaped having a first surface, a second surface, and an annular sidewall between the first surface and the second surface, the second surface further comprising a clamping groove, the membrane support comprising at least a ventilator and at least a diversion opening, wherein the membrane support has an origin and a radius R, the membrane support comprises a central region within a round region between the origin and ⅔ R, and a peripheral region within a ring region between ⅔ R and R, the ventilator is disposed in the central region, the diversion opening is disposed in the peripheral region; and the annular part of the membrane and the annular sidewall of the membrane support form a gap so that the annular part of the membrane and the annular sidewall of the membrane support are not in contact; and a membrane supported by the membrane support, and the membrane comprises: a disk-shaped part disposed on the first surface of the membrane support; an annular part surrounding the annular sidewall of the membrane support; and a clamping flange engaged in the clamping groove.