Hyperspectral imaging of Si submicron-hole arrays fabricated by electron beam lithography and ultraviolet laser writing lithography

Abstract This study demonstrates that the hyperspectral imaging of reflectance can detect differences in the structural uniformity of silicon submicron-hole arrays (Si SHAs) fabricated using electron beam lithography (EBL) and ultraviolet laser writing lithography (LWL) for nanoimprint molds. Scanning electron microscopy revealed that the Si SHAs obtained using EBL exhibited high geometrical uniformity. The average reflectance spectrum was used as a standard to determine the root-mean-square error (RMSE) values for a comparison of the EBL and LWL patterns. RMSE mapping was used to visualize the differences in geometrical parameters and structural variations. The Si SHAs obtained via LWL exhibited gradual changes in diameter and pitch around the boundaries during laser scanning. Finite-difference time-domain simulations indicated that the variations in the reflectance spectra were mainly due to variations in the hole diameter and pitch, which led to a modulated periodic lattice resonance associated with the Bloch mode.