Abstract

ArF excimer lasers are one of the most promising candidates as light sources for 1-Gbit DRAM microlithography. The required light spectrum width for this application is about 1 pm, due to inherent color aberration problems in stepper lenses made only of quartz. However, it is difficult to achieve spectral narrowing of less than 1 pm in ArF excimer lasers, because optical loss caused by dispersive optics is higher and laser gain is lower than in KrF excimer lasers.

© 1996 Optical Society of America