Defect Annihilation in the Directed Self-Assembly of Block Copolymers in Films with Increasing Thickness.

Journal Article · Tue Oct 22 04:00:00 EDT 2019 · Macromolecules

DOI:https://doi.org/10.1021/acs.macromol.9b01030· OSTI ID:1821003

Chen, Xuanxuan; Delgadillo, Paulina R.; Jiang, Zhang; Craig, Gordon S. W.; Gronheid, Roel; Nealey, Paul F.

We investigate directed self-assembly (DSA), with 3x density multiplication, of symmetric polystyrene-block-poly(methyl methacrylate) (L-0 = 28 nm) with increasing film thicknesses and reveal a thickness limit above which the defect annihilation mechanism is different than in thinner films. Block copolymer films of increasing thickness underwent DSA on a macroscopic chemical pattern under optimum geometrical and chemical conditions. Scanning electron microscopy and grazing-incidence small-angle X-ray scattering (GISAXS) were used to characterize the long-range ordering and buried structures as a function of film thickness and thermal annealing time. Rotational GISAXS measurements revealed a critical thickness of similar to 3L(0,) below which defect annihilation is cooperative across the film depth and above which it is faster at the free surface than in the film's interior. In the latter case, defects can persist in the film's interior despite perfect assembly and registration at the free surface of the film.

• Research Organization: Argonne National Laboratory (ANL)
• Sponsoring Organization: National Science Foundation (NSF); USDOE Office of Science - Office of Basic Energy Sciences - Scientific User Facilities Division
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 1821003
• Journal Information: Macromolecules, Journal Name: Macromolecules Journal Issue: 20 Vol. 52; ISSN 0024-9297
• Country of Publication: United States
• Language: English