Multicomponent negative-type photoresist based on Noria analog with 12 ethoxy groups

The characteristics of Noria analogs with 12 ethoxy groups and 12 hydroxy groups (Noria-OEt), which were synthesized by the condensation reaction of 3-ethoxyphenol with 1,5-pentanedial, were examined in detail. The solubility of the synthesized Noria-OEt in common organic solvents was better than that of Noria. In addition, Noria-OEt was soluble in 2.38wt% tetrametyl ammonium hydroxide (TMAH) aqueous as a developer. The thermal stability and mechanical properties were similar to those of Noria because of the ladder structure and amorphous characteristics, which means that the film-forming properties were confirmed. These characteristics are advantageous for use as a molecular glass photoresist. The patterning properties of the negative-type, alkaline developable, multicomponent photoresist based on Noria-OEt, with polyfunctional benzyl alcohols as a crosslinker and a photoacid generator, were evaluated with an extreme ultraviolet lithography system. This negative-type photoresist with 2,4-dihydroxymethyl-6-methylphenol as a crosslinker gave a resolution pattern of 35 nm half-pitch with 10.0 mJ cm(-2). Polymer Journal (2011) 43, 407-413; doi:10.1038/pj.2010.146; published online 9 February 2011