We report on the development of a new measurement method, resonant critical-dimension small-angle x-ray scattering (CD-SAXS), for the characterization of the buried structure of block copolymers (BCP) used in directed self assembly (DSA). We use resonant scattering at the carbon edge to enhance the contrast between the two polymer blocks and allow the determination of the 3D shape of the native lamella in a line-space pattern. We demonstrate the method by comparing the results from conventional CD-SAXS to resonant CD-SAXS on a 1:1 DSA-BCP sample with a nominal 50 nm pitch. The resonant CD-SAXS method provides substantially improved uncertainty in the fit of the line shape and allows the determination of the buried structure.
Citation: Journal of Micro/Nanolithography, MEMS, and MOEMS
Pub Type: Journals