Laser Precision Engineering: from Micro-scale to Nano-scale

Laser precision engineering in ambient air has unique advantages as a non-contact and high-speed process. It is a key advanced manufacturing approach for high quality micro/nano-structures’ fabrication. In the past decades, we have witnessed its extensive applications in research laboratories and production lines. Combined with some advanced processing tools, such as AFM and NSOM, laser precision engineering’s resolution can be pushed down to 10 ~ 25 nm, much smaller than Optical Diffraction Limit, which provides an excellent opportunity for the nano-manufacturing. In this talk, the physics behind laser-matter interactions will be reviewed. How to achieve small heat affected zone (HAZ) is one critical challenge for high quality laser precision engineering to push its resolution from micro-scale to nano-scale. The next critical challenge is how to ensure high enough nano-fabrication speed to meet industrial needs. Since one beam laser processing at high resolution could not achieve such mission, parallel laser beam processing is developed to cater for both high resolution and high speed at the same time. Another challenge is how to carry out the laser nano-structuring in far field as the near field processing requires the tiny optics working very close to sample surfaces, which makes the laser nanofabrication in near field be only suitable for very limited super-smooth surface samples. Our recent research shows that hybrid pulsed laser processing in far field and in ambient air is a novel method to make ~15 nm features directly on Si surfaces. With better understanding of the complicated physics behind this unique experimental result, as well as further fine tuning of our experimental setup and laser processing parameters, it is highly possible to bring our laser precision engineering resolution down to ~10 nm.