Laser spike annealing of DSA photoresists

The thermodynamic mismatch of different segments in a block copolymer drives microphase separation, while their covalent bonds limit the phase separated domains to the nanometer scale. As a result, densely arranged high resolution patterns, the goal of lithography, form a thermodynamically preferred equilibrium state for block copolymers. For production new annealing methods are being explored to speed up and improve structure formation. Solvent vapor annealing is a powerful technique to control the ordering process and the morphology of block copolymers by selectively or non-selectively swelling polymers. In recent years high χ block copolymers are attracting more and more attention due to their potential to form small patterns. However, the ordering process of high χ block copolymer is kinetically slow, thus using solvent vapor or increased temperature to enhance the polymer chain mobility is a key to increase ordering rate. In this paper, we review recent work on using solvent annealing to control the morphology and report high speed laser annealing of high χ for lithographic applications.