Feasibility and applicability of integrated metrology using spectroscopic ellipsometry in a cluster tool

For any industrial integrated metrology application three key issues must be addressed-feasibility, applicability and cost-effectiveness. This paper reports progress on the integration of spectroscopic ellipsometry (SE) in the cool-down chamber. SE is capable of providing rapid information on layer thickness, composition, crystallinity, surface roughness, etc. However, major issues remain to be addressed for integration in commercial tools, including development of compact hardware with high stability and accuracy to fit in the accessible space, automatic alignment and movement systems, and calibration of chamber access windows. Potential uses of integrated metrology are for rapid process development, evaluation of in situ cleaning, measurement of multiple processes without exposure to atmosphere, accurate measurement of layers obscured by later processing, run-to-run, chamber-to-chamber and tool-to-tool repeatability and control, evaluation of cross-wafer uniformity, go/no go decision making after each p...