Pulsed Laser Interference Patterning of Metallic Thin Films

Pulsed laser interference is applied to metallic and semiconductor thin films in the thickness range of 40-100 nm. At intensities which induce local melting we can observe local retraction of the molten material towards the unmolten areas due to dewetting. Thus micropatterning of surface gets feasible. Although this dewetting induced retraction should be a common behaviour of metals on oxide surfaces, two groups of materials can be distinguished. In the first group the former molten areas get completely blank of metal while in the second group a material droplet remains in the center of the molten area. We show that this behaviour can be attributed to a distinctly different way of liquid movement upon local melting.