Planarization of a layer of metal and anodic aluminum

摘要

A planarization method of fabricating a layer of metal conductors embedded in a dielectric level. A coating of aluminum is anodized from the top but leaving a thickness of unanodized aluminum on the bottom. The top is masked and etched to provide a predetermined bare area which is etched out down to the unanodized aluminum. A metal is plated to the unanodized aluminum equal to the thickness of the unexposed anodic aluminum. The mask is removed and the unanodized aluminum is anodized. Therefore, the layer of metal and the dielectric anodic aluminum are planarized. Another anodizable metal may be used as an undercoat layer for completing the anodizing of the aluminum.