Fabrication of metal grating by holographic lithography system

The periodic metal grating is fabricated on SiO₂ substrate by holographic lithography and stripping technology. The exposure in holographic lithography is adopted with optimized exposure time of 70s. The metal Al mask is deposited on the substrate by magnetron sputtering system. Images of scanning electron microscopy(SEM) and atomic force microscopy(AFM) show that the metal grating has a period of 528nm, duty cycle of 0.5, thickness of 95nm, with perfect surface morphology, good fringe continuity and uniformity.