Patterning of polystyrene thin films by solvent-assisted imprint lithography and controlled dewetting

This paper presents an innovative approach for the preparation of polystyrene (PS) micropatterns by using solvent-assisted imprinting lithography and demonstrates a controlled dewetting process for fabricating an ordered nanostructure from a polymer thin film. Uniform PS pattern can be fabricated at room temperature and low pressure (0.01 MPa) by a solvent-assisted imprinting method. The imprinted PS microlens marked change in morphology from dome to sphere because a spinodal dewetting process occurs after the acetone treatment. By adjusting the thickness of residual layer between imprinted domes, the orderly self-organized PS sphere arrays with bimodal and even multiple sizes can be fabricated. The combination of solvent-assisted imprinting and templated self-organization can be an effective method for the preparation of complex patterns with multiple sizes, which is not easy to be obtained with conventional photolithography process. Furthermore, the sub-micrometer PS pre-pattern can turn into photonic crystal arrays with 550 nm pitch by this dewetting process.

Graphical abstractA self-organization process based on spinodal dewetting of a patterned thin PS film has been demonstrated by using a simple and rapid solvent treatment.Figure optionsDownload full-size imageDownload as PowerPoint slide