Stiff thin layers on compliant substrates can generate various surface structures using equi-biaxial stress caused by large thermal expansion rate differences We investigated the detailed understanding on the evolution of self-assembled wrinkle patterns of ultra-thin amorphous silicon (a-Si) layers on polydimethylsiloxane substrate It turns out that the generation of various wrinkle patterns depends on the position of their orientation film thicknesses mechanical properties of the a-Si films and the amount of pre-strain The various self assembled patterns include one-dimensional wavy patterns randomly ordered two-dimensional structured patterns and herringbone structures The self-assembled wrinkles can be characterized by the wavelength and amplitude of the distinct structures the amplitudes of the various patterns increase as the amount of pre strain increases while the wavelengths remain constant within our experimental ranges The experimental results of the wavelengths and amplitudes for the wavy structured patterns of 270-nm-thick a-Si layer are in good agreement with the theoretical solutions of the single crystalline silicon (c Si) model which implies that the theoretical modeling of the deformation of c-Si film can be expandable to the case of a-Si film deformations (c) 2010 Elsevier BV All rights reserved