SELF-CONSISTENT-FIELD THEORY OF DIBLOCK COPOLYMER MELTS AT PATTERNED SURFACES

Self-consistent field theory is used to investigate the density profil e of diblock copolymer melts in a thin film confined between two surfa ces, one of which carries a chemically active pattern. The temperature is slowly lowered through the critical point in order to obtain well organized structures. For strong surface interactions, the lamellae fo r symmetric diblock copolymers comply with the surface pattern. Their orientation depends on the ratio of natural bulk period L-0 to surface period L. For L(0)less than or equal to L, the lamellae tilt at an an gle theta= arcsin L-0/L with respect to the surface, For L(0)greater t han or equal to L, the diblocks are distorted close to the surface and the necessary relaxation off the surface induces parallel oriented la mellae with respect to the surface for films thicker than 2 lamellar p eriods. Very thin films still support the perpendicular orientation. ( C) 1998 American Institute of Physics.