In this paper, a physical model for the development of dishing during metal chemical mechanical polishing (CMP) is proposed. The main assumption of the model is that material removal occurs predominantly at the pad/wafer contacts. The distribution of pad/wafer contact size is studied first. This distribution is used as an input for a model of the dependence for the material removal rate on the line width. A relation that describes the development of dishing as a function of overpolish time will be presented. The model describes to a great accuracy the observed dishing effects, using one free parameter.
|Title of host publication
|International Electron Devices Meeting 2000. Technical Digest. IEDM
|Place of Publication
|Institute of Electrical and Electronics Engineers
|Number of pages
|Published - 1 Jan 2000