AFM study of excimer laser patterning of block-copolymer: Creation of ordered hierarchical, hybrid, or recessed structures

• Published in: Applied surface science 2016-05, Vol.371, p.203-212
• Main Authors: Švanda, Jan, Siegel, Jakub, Švorčík, Vaclav, Lyutakov, Oleksiy
• Format: Article
• Language: English
• Subjects: Block copolymers; Block-copolymer; Blocking; Excimer laser patterning; Excimer lasers; Lasers; Non-polarized vs. polarized laser beam; Patterning; Phase separation; Polystyrene resins; Self assembly; UV–vis and AFM study; XPS
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2016.02.234

[Display omitted] •Combination of bottom-up (BCP separation) and top-down (laser patterning) technologies allows obtaining hierarchical structures.•Surface morphologies were determined by the order of patterning steps (laser modification, annealing, surface reconstruction).•Tuning the order of steps enables the reorientation of BCP domain at large scale, fabrication of hierarchical, hybrid or recessed structures.•The obtained structures can find potential applications in nanotechnology, plasmonics, information storage, sensors and smart surfaces. We report fabrication of the varied range of hierarchical structures by combining bottom-up self-assembly of block copolymer poly(styrene-block-vinylpyridine) (PS-b-P4VP) with top-down excimer laser patterning method. Different procedures were tested, where laser treatment was applied before phase separation and after phase separation or phase separation and surface reconstruction. Laser treatment was performed using either polarized laser light with the aim to create periodical pattern on polymer surface or non-polarized light for preferential removing of polystyrene (PS) part from PS-b-P4VP. Additionally, dye was introduced into one part of block copolymer (P4VP) with the aim to modify its response to laser light. Resulting structures were analyzed by XPS, UV–vis and AFM techniques. Application of polarized laser light leads to creation of structures with hierarchical, recessed or hybrid geometries. Non-polarized laser beam allows pronouncing the block copolymer phase separated structure. Tuning the order of steps or individual step conditions enables the efficient reorientation of block-copolymer domain at large scale, fabrication of hierarchical, hybrid or recessed structures. The obtained structures can find potential applications in nanotechnology, photonics, plasmonics, information storage, optical devices, sensors and smart surfaces.