VUV laser photolithography

An F2 excimer laser at 157 nm has been used for the first time as an exposure source for high resolution photolithography. At this short wavelength, conventional glass and quartz mask substrates are opaque, and therefore alkaline‐earth halides and sapphire were used as mask substrates. The masks were patterned by e‐beam lithography and mask features as narrow as 150 nm have been replicated and represent the smallest features yet produced by contact photolithography.