Method and apparatus for conditioning a cmp pad

Abstract

The present invention relates to a method and apparatus for conditioning a polishing pad used in chemical mechanical polishing in which a consistent pressing force can be provided between an abrasive conditioning member and the polishing pad. Specifically, a moveable weight member is provided that can be selectively moved along a length of a support arm in the conditioning apparatus. The position of the weight member relative to the position at which the abrasive conditioning member is mounted alters the resultant pressing force in view of the change in moment created. In a particular example, the positioning of the weight member can be automatically controlled using a drive mechanism controlled by a control unit, such as a computer. In a more particular example, the positioning of the weight member can be dynamically controlled if the control unit receives an external feedback upon which its control of the weight member position is based, such as a detected value of the pressing force exerted by the abrasive conditioning member. Finally, if the apparatus is appropriately arranged to permit the weight member to travel to an opposite side of the location at which the support arm is mounted from the abrasive conditioning member, then a 'negative pressing force' can be generated, such that effective pressing forces less than the resting weight of the pad conditioning apparatus can be realized.