Roller-based laser-assisted direct imprinting for large-area and continuous nano-fabrication

This paper presents an innovative approach for large-area and continuous nano-fabrication on silicon substrates based on laser-assisted direct imprinting (LADI) method, which utilizes a pulsed laser for direct forming nano-structures on a substrate from a quartz mold. The key point is to introduce a quartz roller in this LADI process. The quartz roller optically focuses an incident laser beam into a line and mechanically creates a concentrated pressure distribution along the laser focusing line. With properly chosen laser fluence and contact pressure, nano-structures are fabricated at area around the focusing line. By moving the mold/substrate and triggering the laser pulses continuously, the whole surface features of the quartz mold can be transferred to the substrate in a fast, direct, and continuous way. Experimental testing of this roller-based LADI process has been carried out successfully, and it demonstrates several significant improvements and advantages over conventional planar-type LADI. Potential applications of this roller-based LADI for nano-patterning and nano-fabrication will be addressed.