Boundary-Directed Epitaxy of Block Copolymers Toward Sub-10 nm Fabrication

Abstract

The directed self-assembly (DSA) of block copolymers (BCPs) can be used to produce nanometer-scale patterns without the cost and process complexity of state-of-the-art optical nanolithography. Thus, DSA is of potential use in a wide variety of semiconductor technologies, such as finFETs and biosensors. To control the position and orientation of BCP domains and create technologically useful patterns, conventional DSA mechanisms often rely on topographically complex structures or high-resolution chemical patterns that are difficult to fabricate. In comparison, a newly discovered mechanism for the DSA of BCPs – termed “boundary-directed epitaxy” – utilizes the chemical contrast at the boundaries between a substrate and relatively wide chemical stripe.[1] As a result, aligned and high density-multiplied BCP nanopatterns with half-pitch of 6.4 nm have been created using stripes as wide as 100 nm. By obviating the need for high-resolution chemical patterns, boundary-directed epitaxy offers exciting opportunities for the fabrication of sub-10 nm nanostructures.[1] Boundary-directed epitaxy of block copolymers. R.M. Jacobberger, V. Thapar, G.-P. Wu, T.-H. Chang, V. Saraswat, A.J. Way, K.R. Jinkins, Z. Ma, P.F. Nealey, S.-M. Hur, S. Xiong, M.S. Arnold, Nature Communications 11, 4151 (2020), 10.1038/s41467-020-17938-3. Figure 1