Influence of underlay thickness on the period of nanoscale wrinkle

The influence of underlay thickness on the wrinkle period has been explored in this paper. The wrinkle period has been reduced to about 600 nm on an ultrathin Au upper-layer/polystyrene (PS) underlay system. The experimental data show that the wrinkle period is decrease with the underlay thickness. The previous theory can not give an adequate explanation of the relationship between the underlay thickness and the wrinkle period. A new analytical solution containing finite underlay thickness and a stretching energy item is obtained based on Landau's elastic theory. The analytical solution can well explain the relationship between the underlay thickness and the small period, and is consistent with the experimental data.