
146 Semiconductors: Integrated Circuit Design for Manufacturability
Three MfD and DfM solutions were considered to reduce the ower pat-
tern shearing. First, because the process parameters: HF/RF radio frequency
power and ILD dopant concentration were easy to control, the MfD solution
of SAC redevelopment was rejected as more time consuming than adjusting
the mask pattern. As the second option, a DfM approach disallowing SAC in
the periphery was rejected as the one which would result in signicant cost
of relayout and larger footprint. The best, third option, was layout postpro-
cessing by CAD, eventually allowing for the self-aligned trench ...