Grooved polishing pads and methods of use

Abstract

Grooves are formed in a CMP pad by positioning the pad on a supporting surface with a working surface of the pad in spaced relation opposite to a router bit and at least one projecting stop member adjacent to the router bit, an outer end portion of the bit projecting beyond the stop. When the bit is rotated, relative axial movement between the bit and the pad causes the outer end portion of the bit to cut an initial recess in the pad. Relative lateral movement between the rotating bit and the pad then forms a groove which extends laterally away from the recess and has a depth substantially the same as that of the recess. The depths of the initial recess and the groove are limited by applying a vacuum to the working surface of the pad to keep it in contact with the stop member(s). Different lateral movements between the bit and the pad are used to form a variety of groove patterns, the depths of which are precisely controlled by the stop member(s). The grooves may be formed in the polishing surface and/or the rear opposite surface of the pad and passages may be provided for interconnecting the rear grooves with the polishing surface or the front grooves.

Dependencies are inferred from the claim text.