Near-surface relaxation structure of annealed block copolymer film on Si substrates examined by grazing-incidence small-angle scattering utilizing soft X-rays

Two-dimensional grazing-incidence small-angle X-ray scattering (GISAXS) measurements of SEBS8 block copolymer films deposited on Si(001) substrates have been performed to demonstrate depth-sensitive GISAXS utilizing soft X-rays of 1.77 keV. Remarkable elongation of the Bragg spots in the q_z direction, corresponding to microphase separation, was observed for an angle of incidence close to the critical angle. The elongation was explained in terms of the penetration depth, which limits the effective size in the direction perpendicular to the sample surface. Lattice distortion near the surface was confirmed.