Lithography Materials - Directed Self-Assembly of Block Copolymers

In order to use the self-assembled nanostructures from the block copolymers as a viable patterning method in semiconductor device fabrications, controlled assembly and placement control is crucial. In Almaden Research Center, leveraged on the expertise on the photo-lithography, a variety of new approaches including topographic pre-patterns and/or chemical pre-patterns are studied to direct the self-assembled nanostructures. Shown below are the examples of alignment of lamellae into pre-defined patterns. By controlling interactions at the interfaces and scaling of the pre-patterns, parallel, perpendicular and crossbar alignments of the lamellae were achieved. More effort is under way to fully control the self-assembled structure for device fabrications.

Controlled assembly of lamellar phase

In the scheme, red and green represent selective and neutral surface, respectively. Blue represents the lamellae from the self-assembly.