Some problems in 1:1 broadband excimer laser lithography

One of main directions in practical application study of excimer laser lithography is broadband excimer laser lithography. We have developed a new 1:1 broadband catadioptric lens, ( NA:0. 36, field size: 10X10 mm2, wavelength: 308 nm). A special silicon oil is used to cement between quartz glass lens and CaF2 lens, and between CaF2 prisms and quartz glass len6. When excimer laser exposure dose is 220 mJ/cm2.pulse, silicon oil is not evaporated. The transmission of cemented surface is good. We have studied the mask damage in XeCl excimer laser exposure,Three mask damages are discovered .The damage threshold of mask is 300 mJ/cm2.pulse.