Patent attributes
Pad-assisted electropolishing of the substrate is conducted by performing anodic dissolution of metal at a first portion of the substrate and simultaneously mechanically buffing a second portion of the substrate with a buffing pad. Anodic dissolution includes forming a thin liquid layer of electropolishing liquid between the anodic substrate and a cathodic electropolishing head. The location of electrical contacts between the substrate and power supply allow peripheral edge regions of the substrate to be mechanically buffed with the pad. Preferably, a substrate is further planararized using an isotropic material-removal technique. An apparatus includes an electropolishing head that is movable to a position proximate to a first portion of a substrate to form a thin gap, and a buffing pad that mechanically buffs a second portion of the substrate using minimal pressure.
