Micropatterning of Silicon Surface by Direct Laser Interference Lithography

Direct laser interference lithography is a new and low cost technique which can generate the line- or dot-like periodic patterns over large areas. In the present work, we report on direct fabrication of micrometer structures on Si surface. In the experiments the pulsed high power Nd:YAG laser operating at 1064 nm wavelength was used. Two-beam configuration with an angle of incidence of 40° was employed and different laser fluences up to 2.11 J/$cm^2$ were tested. Areas about 1 cm in diameter have been processed with a single pulse of 10 ns. The laser treated samples were analyzed by atomic force microscopy to investigate the surface topography and to measure the size and depth of the achieved structures. We observed periodic line-like arrays with grating period of the order of 1 μm.