INSOLUBILIZATION MECHANISM OF A CHEMICAL AMPLIFICATION NEGATIVE-RESIST SYSTEM UTILIZING AN ACID-CATALYZED SILANOL CONDENSATION REACTION

A chemical amplification system for negative resists, utilizing a solubility-reversal mechanism, is described. The new system consists of a radiation-induced acid generator, a novolak matrix resin, and a silanol compound. Silanol compounds show chemical affinity to aqueous alkali solution and can act as dissolution promoters in aqueous alkali developers. In contrast, the condensation reaction products of silanol compounds, siloxanes, are typical hydrophobic materials and can therefore act as dissolution inhibitors in aqueous developers. The resist system resolves 0.3-mu-m line and space patterns by using electron-beam delineation (exposure dose 0.8-mu-C/cm2 at 30 kV). The condensation reaction products of silanol compound in the exposed areas were detected by gel permeation chromatography. The insolubilizing mechanism of the new resist system is discussed.