Gary Charles Davis

Contrast Enhancement Materials For Mid-Uv Applications

The use of nitrones as contrast enhancement materials has been extended to the mid-UV region. Diarylnitrones, which function effectively as near-UV contrast enhancement materials, have been found to be less suitable for mid-UV printing because of secondary photochemical reactions. α-Aryl-N-alkylnitrones, however, can be designed to absorb efficiently and photobleach cleanly over a wavelength range of about 280 to 350 nm. Arylalkylnitrones are much more resistant to hydrolysis than are their diaryl counterparts and have been successfully formulated as aqueous solutions. Submicron resist patterns have been printed with a scanning projection aligner operating in the mid-UV through the use of a contrast enhancement material based upon an arylalkylnitrone.