The advent of integrated metrology (IM) for lithography critical dimension (CD) control has been
widely discussed and debated. A number of factors are pushing chip makers in the direction of
IM implementation, including shrinking line widths and decreasing CD budgets, higher throughput
Litho cells, escalating cost and impracticality of stand-alone CD metrology, and reducing
overhead (or non value-add) time. These factors combine to make the question of IM for CD
control "when" rather than "if".
Scatterometry can provide a wealth of information about structures on a wafer including CD,
sidewall angle, and film thickness for various layers. Although this information unquestioningly
provides additional insight into the lithography process, in the end, the rate of IM implementation
depends on its return on investment (ROI). In this paper, we discuss the implementation of
integrated Optical Digital Profiling (iODPTM) on an advanced lithography track (Tokyo Electron
CLEAN TRACK LITHIUSTM). Included are discussions of lithography trends, metrology
requirements, and IM data flow and analysis. Various strategies for IM implementation are
presented along with their associated ROIs.