CMP Pad Dressing With Oriented Diamond

摘要

The polishing action of CMP takes place between a semiconductor wafer and a polyurethane pad, so its performance is often determined by the texture of the pad surface. The texture of the polishing pad is carved out by a diamond dresser. In this paper we presented for the first time the data of a single diamond grit with the controlled diamond orientation to realize the characteristics of dressing action on the pad. A stylus type 3-dimensional surface roughness measuring instrument is used to map the 3D topography of the dressed surface on the pad. The results demonstrated that the profile of the scratch is correlated with the orientation of the diamond, but it does not change significantly with increasing dressing velocity. Plastically deformed ridges form when a diamond plows out a groove. The largest width and height of the ridge is created by diamond crystals with 3D orientation, and the height of the ridge increases with the increasing depth of cut. In addition, when two grooves cross each other, the ridges in the intersected area pile up each other and become the highest points on the pad surface.