Application and cost analysis of scatterometry for integrated metrology

In semiconductor manufacturing there is a great demand for innovations towards higher cost-effectiveness. The increasing use of integrated metrology is one means to improve manufacturing processes effectively and, hence, to lower costs. Especially for the 300 mm technology, a substantial reduction of costly monitor wafers is required. Moreover, misprocessing has to be reduced by efficient feedback process control. Scatterometry can be a versatile technique for these tasks. In order to define the requirements on integrated scatterometric metrology, a cost and break-even analysis is carried out first. Several conclusions are drawn from the economic analysis to determine appropriate arrangements for scatterometric intensity measurements. The evaluation of intensity signatures measured at a fixed angle of incidence is demonstrated to be a valuable tool for the in-line characterization of critical dimensions and layer thickness.