The fabrication of high-performance diffraction gratings via vibration-assisted UV nanoimprinting lithography

With the aim of improving the performance of diffraction gratings, a piezoelectric-driven vibration-assisted UV nanoimprint method is proposed for use in the fabrication of diffraction gratings. It is found that by introducing one-dimensional lateral vibrations with a low-frequency and a low-amplitude into nanoimprinting, the surface quality of the resultant grating is improved and the filling rate of the photoresist in the mold is enhanced. The influence of the grating properties on the diffraction efficiency was determined via a simulation analysis, and the effects of the vibration frequency and vibration amplitude on the filling rate were studied; via these studies, a series of parameters describing the imposed vibrations that are expected to be suitable for use in the vibration-assisted UV nanoimprinting method is obtained. Furthermore, a novel asymmetric vibration stage is designed. The performance of the vibration-assisted UV nanoimprinting method was verified via scanning electron microscopy. Under the illumination of a light source, the measured diffraction angle is consistent with that predicted using the diffraction equation. The results indicate that vibration-assisted UV nanoimprinting method can accurately fabricate diffraction grating structures with superior performance compared with gratings obtained via other methods.