Aqueous base developable deep-UV resist based on chemically amplified crosslinking of phenolic resin

The principle of chemical amplification has proven to be successful for the design of highly sensitive, high resolution resist material. In many cases a strong Broensted acid, generated by photolysis of onium salt precursors, has been used to catalytically cleave an acid labile blocking moiety. A new approach to negative tone resist is based on acid catalyzed cleavage of acetal blocked aromatic aldehydes, which act as «latent electrophiles» and, under the influence of strong acid, react with the surrounding phenolic resin