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A novel bilayer is introduced, consisting of a stiff film adhered to a soft substrate with patterned holes beneath the film/substrate interface. To uncover the transition of surface patterns, twodimensional plane strain simulations are performed on the defected bilayer subjected to uniaxial compression. Although the substrate is considered as the linear elastic material, the presence of defects can directly trigger the formation of locally ridged and then folding configurations from flat surface with a relatively small compressive strain. It is followed by the co-existing phases of folds and wrinkles under further overall compression. This phase transition reverses the traditional transition of wrinkle-to-ridge/fold for defect-free substrates. It's also found that the onset of initial bifurcation is highly dependent on the spatial configuration and geometries of holes, since the interaction of defects allows more strain-relief mechanisms beyond wrinkling. Furthermore, a rich diversity of periodic surface topologies, including overall waves, localizations, saw-like and coexisting features of folds and wrinkles can be obtained by varying the diameter, depth and spacing of holes as well as compressive strain, which provides a potential approach to engineer various surface patterns for applications.

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