Simple 157-nm interference illumination system for pattern formation

Abstract

It is expected that technological needs will increase to create tinier patterns, since the information communication society requires the massive capacity semiconductor. Reducing the wavelength of the light source is the most powerful method for improving ever-decreasing the minimum feature size of the semiconductor device. 193 nm ArF excimer laser source will be followed by 157 nm F2 excimer laser source for the next generation device down to 32 nm line width. Also, it is predicted that the technology of 157 nm ultra vacuum violet light for super fine pattern formation will be essentially used in memory or logic semiconductor manufacturing, their parts and process development. 157 nm interference imaging lithography system will be built with direct support of 157 nm resist and its process development. A circumstance that reduces the absorption rate due to air, water, O3, and other gases must be made. So, the entire system is enclosed in a N2 purged. The optical interference system was constructed after investigating various optical materials, and it enabled us to test various chemical materials to produce a real pattern by implementing the existing optical system. By using the illumination system that uses Lloyd's mirror interference type, simple interference line and space pattern was obtained.