Fabrication process of flexibly patterned grating by interference lithography system with automated beam alignment module

We report on a new developed interference lithography system that allows flexible design of the slant angle and pattern pitch of the diffraction grating. The system consists of two optical paths moving on an arc stage and another stage moving horizontally with precision, allowing the slant angle and pattern pitch to be controlled up to +/- 25 degrees and from 150 to 500 nm, typically. In addition, this system is equipped with a fine stage for semiconductor lithography, diode-pumped solid-state lasers with wavelengths of 266 nm and 355 nm, and a high-resolution actuator to achieve 0.01 nm pitch accuracy and high contrast exposure. Slant gratings with different angles and directions depending on their position on a wafer can be processed with this system. This presentation will also introduce various structures developed with this system and examples of their potential applications.