Fabrication of Micro-Size Structures using Scanned Interference Pattern

Interference of several identical laser beams allows fabrication of periodical structures over large areas. Scanned interference pattern method for increased patterning flexibility of thin metal films is proposed. Periodical arrays of circular holes were fabricated by 6 interfering beams. By displacing the sample in small steps between laser shots, holes can be overlapped and structures independent on interference intensity distribution can be obtained. Slit and cross-shaped structures were fabricated in various metal films using direct structuring with nanosecond pulses. Cross-shaped periodical structures in thin films can be applied as band bass filters for terahertz and infrared radiation. Peak frequency and band width of fabricated pattern was calculated and influence of rounded corners of the crosses evaluated.