  We investigate spreading of phase separated copolymer films, where domain
walls and thickness steps influence polymer flow. We show that at early stages
of spreading its rate is determined by slow activated flow at terrace steps
(i.e. thickness steps). At late stages of spreading, on the other hand, the
rate is determined by the flow along terraces, with diffusion-like time
dependence $t^{-1/2}$. This dependence is similar to de Gennes and Cazabat's
prediction for generic layered liquids, as opposed to the classical Tanner's
law of drop spreading. We also argue that chain hopping at the spreading
terrace steps should lead to the formation of aligned, defect-free domain
patterns on the growing terraces.
