Development of inclined UV lithography with liquid-immersion

Abstract

This paper reports on development of inclined UV lithography with liquid-immersion. Conventional fabrication methods had limitations in the inclination angle of structures due to the difference in refractive index between materials. The proposed fabrication method applies liquid immersion exposure from semiconductor process, allowing structures to be made in a higher inclination angle than previously reported. The developed device consists of two adjustable mirrors and water chamber attached to a cubic prism. UV light rays reflect off mirrors and pass through the cubic prism to expose the glass wafer without air. The device was able to produce an array of inclined structures on glass wafer. The results suggest increase in inclination angle of structures. In addition, the flexibility of the inclination angle allows improvements in the performance of three-dimensional MEMS structures.