Flat metal features for microelectronics applications

Abstract

Advanced flat metals for microelectronics are provided. While conventional processes create large damascene features that have a dishing defect that causes failure in bonded devices, example systems and methods described herein create large damascene features that are planar. In an implementation, an annealing process creates large grains or large metallic crystals of copper in large damascene cavities, while a thinner layer of copper over the field of a substrate anneals into smaller grains of copper. The large grains of copper in the damascene cavities resist dishing defects during chemical-mechanical planarization (CMP), resulting in very flat damascene features. In an implementation, layers of resist and layers of a second coating material may be applied in various ways to resist dishing during chemical-mechanical planarization (CMP), resulting in very flat damascene features.