Swift nanopattern formation of PS-b-PMMA and PS-b-PDMS block copolymer films using a microwave assisted technique.

Microphase separation of block copolymer (BCPs) thin films has high potential as a surface patterning technique. However, the process times (during thermal or solvent anneal) can be inordinately long, and for it to be introduced into manufacturing, there is a need to reduce these times from hours to minutes. We report here BCP self-assembly on two different systems, polystyrene-b-polymethylmethacrylate (PS-b-PMMA) (lamellar- and cylinder-forming) and polystyrene-b-polydimethylsiloxane (PS-b-PDMS) (cylinder-forming) by microwave irradiation to achieve ordering in short times.

Orientation and alignment control of microphase-separated PS-b-PDMS substrate patterns via polymer brush chemistry.

Block copolymer (BCP) microphase separation at substrate surfaces might enable the generation of substrate features in a scalable, bottom-up fashion, provided that the pattern structure, orientation, and alignment can be strictly controlled. The PS-b-PDMS (polystyrene-b-polydimethylsiloxane) system is attractive because it can form small features and the two blocks can be readily differentiated during pattern transfer. However, PS-b-PDMS offers a considerable challenge, because of the chemical differences in the blocks, which leads to poor surface wetting, poor pattern orientation control, and structural instabilities.

Polymer nanostructures in sub-micron lithographically defined channels: film-thickness effects on structural alignment of a small feature size polystyrene-polyisoprene-polystyrene block copolymer.

The use of phase separation in block copolymer systems to generate regular nanopatterns at surfaces may be an alternative to advanced photolithography. Here, substrates with photolithographically defined rectangular channels (of depth 60 nm and widths 166-433 nm) are used to direct nanoscale phase separation of a polystyrene--polyisoprene--polystyrene (PS-PI-PS) block copolymer into aligned periodic superstructures. This nanoscale phase separation results in the rapid formation of parallel and narrow polystyrene (PS) cylinders orientated in a 2D hexagonal arrangement within a polyisoprene (PI) matrix for the polymer composition used here.