Laser Interference Lithography

Laser Interference Lithography (LiL) can be used for exposure of periodic structures in photoresist. To this end, two coherent beams are expanded and superimposed (see photo). Large-scale substrate structuring with line densities of more than 4000 lines per mm would exceed the capabilities of UV lithography. The impact of sinusoidal resist profiles on the following process steps is part of our research.

Set-up for Laser Interference Lithography (LIL)

Laminar grating in photo resist

Wet-chemically etched blaze grating