Lithography budget analysis at the process module level

A simple experimentally characterized lumped-parameter budget model is developed with the goal of quantifying the most significant components of critical dimension (CD) variation through an integrated process module. Tracked components include mask fabrication budgets, mask error factor, scanner field variation, optical proximity correction error, CD errors over chip topography, wafer-to-wafer and lot-to-lot variation. The components of variation are quantified for lithography and etch where appropriate and are fed into a simple interaction model to construct an overall patterning module CD budget. Normalized experimental results for this budget analysis are presented for 65 nm technology node contact patterning processes.