A feature scale Greenwood–Williamson model predicting pattern-size effects in CMP

Chemical mechanical planarization (CMP) models which are able to make predictions on the chip and feature scale are highly desirable in semiconductor manufacturing. Most of the models proposed in the past years have largely focused on the pattern density and neglected effects of pattern size in planarization. We here propose a new CMP feature scale model that incorporates size effects by considering the roughness of the polishing pad. It is validated by experimental data from CMP test structures containing variations of both pattern-density and -size. The results are applied to ILD- and STI-CMP as particularly important processes in industry. The derived model describes the feature step height and shape evolution with high accuracy throughout the planarization process.

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