Theoretical analysis of laser-induced periodic structures at silicon-dioxide/silicon and silicon-dioxide/aluminum interfaces

An analytical model was established to predict the laser-induced periodic structures at silicon-dioxide/silicon and silicon-dioxide/aluminum interfaces. The freezing of surface waves is considered the dominant mechanism for ripple formation. The model precisely predicts a linear relationship between the interface periodicity and the silicon dioxide thickness. The ripple periodicity in the substrates can hence be adjusted by varying the thickness of SiO2 overlayer. This process is expected to be useful in laser microtexturing for magnetic media of high storage density, which requires microtextures to be well controlled within a certain roughness to prevent a stiction failure. The theoretical calculation has a good agreement with the experimental results.