Liquid-immersion inclined UV lithography using cube prism and mirrors

This paper reports on the inclined UV lithography based on liquid immersion. The proposed method implements liquid immersion, allowing structures to be formed with a large inclination angle. The equipment comprises two adjustable mirrors and a cubic glass with a pure water chamber. UV light rays are reflected and passed through the mirrors and chamber, irradiating the target at an inclined angle. We developed the necessary equipment and fabricated the 3D microstructures. The results revealed that the inclination angle reached up to 49°, indicating exposures beyond the limits of conventional inclined UV lithography.