Silicon-containing block copolymers for lithographic applications

Abstract This comprehensive review, summarizes recent advances in the fabrication of well-ordered block copolymer (BCP) thin films by different methods, focusing on the development of silicon-containing BCPs as candidates for lithographic applications. With the advantage of Si-containing blocks, these BCPs offer much smaller feature sizes due to large segregation strength and high etch contrast for the fabrication of well-defined nanopatterns with high resolution. Considering that poly(dimethylsiloxane) (PDMS)-containing BCPs are widely studied systems among Si-containing BCPs, the possibility of using PDMS-containing BCPs for lithographic applications is demonstrated through previous and ongoing key research. BCP lithography will lead to the development of next-generation microelectronic devices by providing a simple and scalable nanopatterning method for the fabrication of microelectronic devices in which the feature sizes and geometries are controlled by tuning the chain lengths and volume fractions of the block copolymers. The control of microdomain orientation and alignment in thin film BCPs is crucial for lithographic applications. The principles and limitations of various methods to orientation are discussed, including temperature-gradient, surface modifications, solvent annealing/evaporation and other new types of annealing process. Directed self-assembly (DSA) of BCP on topographic or chemically patterned substrates has attracted a great attention from academic and industrial research since it offers the advantage of defect free nanopatterning at large scales. The key achievements in DSA methods are elaborated in the subsequent parts of this review. New trends for lithographic applications and the applications beyond lithography using Si-containing BCPs for nanopatterning are also discussed, and finally, concluding remarks and perspectives for BCP lithography are presented.