Fabrication of high precision grating patterns with a compliant nanomanipulator-based femtosecond laser direct writing system

Abstract

Femtosecond laser direct writing (LDW) is an enabling technique in the fabrication of micro-/nano-scale devices. In a typical LDW system, the high precision motion system serves as the key component for micro-/nano-fabrication. In this paper, a cost-effective LDW system is proposed with a self-developed compliant nanomanipulator. The accuracy of the LDW system with the proposed nanomanipulator is validated through the fabrication of optical grating patterns with micro-scale feature sizes (<3 μm). The optical grating patterns are fabricated with different spacings, scan speeds and laser powers, and surface characterization and quantitative analysis of the samples are conducted. The characterization results demonstrate that the proposed LDW system is capable of controlling the spacing accuracy within 300 nm in a millimetre-level working range. Compared with the existing commercial laser direct writing system of sub-micrometer level motion accuracy, the proposed compliant nanomanipulator-based femtosecond laser direct writing system achieves comparable performances with much lower costs, and it has broad potential applications to sub-micron level laser direct writing fabrication.