Physical design and mask optimization for directed self-assembly lithography (DSAL)

In DSAL, contact holes are indirectly formed through guide patterns (GPs). Thus the integrity of GPs is very important, in particular when GP shape is large and complex. The limitation in GP shape calls for careful consideration in physical design stage. In mask optimization, synthesizing ideal GP shape and verifying whether synthesized GP is correct are important but difficult problem. Some challenges in physical design and mask optimization are reviewed in this paper with possible solutions.