Three-dimensional wafer scale hydrodynamic modeling for chemical mechanical polishing

Abstract

Chemical mechanical polishing (CMP) refers to a surface removal process done by rubbing a work piece against a polishing pad under load in the presence of chemically active slurry containing an abrasive. The CMP process is a combination of mechanical action and chemical dissolution. The mechanical action of CMP includes hydrodynamic behavior. The slurry fluid trapped between the work piece and the polishing pad forms a hydrodynamic film. Firstly, to understand the surface removal mechanism of the CMP process, hydrodynamic analysis was carried out on full-scale semiconductor wafers. The three-dimensional Reynolds equation was applied to obtain distributions of thickness and pressure of the slurry fluid on the wafer surface. The distribution of contact shear stress of the slurry was also analyzed. (C) 2001 Elsevier Science B.V. All rights reserved.