Skip to main content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.


The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Measuring the Structure of Epitaxially Assembled Block Copolymer Domains with Soft X-ray Diffraction



Gila Stein, James A. Liddle, Andrew Aquila, Eric M. Gullikson


The size, shape, and roughness of poly(styrene-b-methyl methacrylate) block copolymer domains assembled on an epitaxial template are characterized with soft x-ray diffraction. The domain size and shape are deformed when the dimensions of the epitaxial template are incommensurate with the equilibrium dimensions of the block copolymer, producing sidewall angles in the range of 1 deg. to 2 deg. (+/-0:2 deg.). The average width of the copolymer interface is (4.9 +/- 0.08) nm. Comparison with mean-field theoretic predictions for the structure of block copolymer interfaces suggests a low-frequency variance in the copolymer interface position of 0.3 nm^2,or a low-frequency line-edge roughness of approximately 1.7 nm. This roughness magnitude is less than predicted by capillary wave models for copolymer interfaces, and may indicate suppression of longer-wavelength fluctuation modes due to substrate pinning or block connectivity.


line-edge roughness, diblock, self-assembly, directed assembly
Created November 30, 2009, Updated February 19, 2017