Fabrication of a two-dimensional diffraction grating with isolated photoresist pattern structures

This paper presents a fabrication method of a two-dimensional (2D) diffraction grating with isolated photoresist pattern structures in order to reduce fluc-tuation in the grating pitch due to the thermal expan-sion. At first, theoretical calculations for the fabrication of a 2D diffraction grating with isolated pho-toresist pattern structures are carried out to estimate the influences of exposure and development time on the pattern structures to be fabricated through the pattern exposure and development process. A diode laser-based compact non-orthogonal two-axis Lloyd’s mirror interferometer system designed in a size of 500 mm × 840 mm is then built on a breadboard for stable mask-less interference lithography. Basic per-formances of the newly developed compact interfer-ometer system are evaluated through the fabrication of 2D diffraction gratings to demonstrate the feasibil-ity of the theoretical calculations and the developed lithography system.