No abstract

Experimental data from the current 0.35pm deep-UV lithographic process was used in conjunction with simulations of future 0.25p.m lithography to provide a means of evaluating the possibility of meeting the National Lithography Roadmap goals for CD and overlay. This study found that the CD control issue has too many components to be captured by the single number listed in the Roadmap. The current magnitude of many of these components looks too large to justify their shrinking down to values consistent with the general 30% shrinks characteristic of our industry. For overlay the Roadmap value is clearly auainable for matched steppers in controlled tests, however unlikely for daily product results on random-matched steppers in a production environment. This study also examined the impact of pushing deep-UV technology to the 0.25tm regime on the process latitudes of dense/isolated lines and upon the poiy endcap.