A Cross‐Linked Positive Resist Derived from Poly(Methacrylonitrile‐co‐Methacrylic Acid)

Abstract

Cross-linked positive resists derived from copolymers of methacrylonitrile (MCN) and methacrylic acid (MAA) have been developed based on the theoretical formula which shows that a large Mw • G~ value is essential to improve the cross-linked positive resist sensitivity, where Mw is the weight-average molecular weight and Gs is the main chain scission efficiency. The cross-linked positive resist consists of P(MCN92-MAAs) with a viscosity-average molecular weight (M~) of 5.7 • 10 ~ and tripropylene glycol diglycidyl ether (TPG) as a cross-linking agent. It has high sensitivity (3 ~C/cm 2) and high dry-etch resistance, reflecting the large Mw • Gs value of the copolymer and the high dry-etch resistance of the MCN component. The resist is applied to a trilayer resist system as the top imaging layer. Submicron fine patterns delineated at 3.4 ~C/cm 2 are transferred to the thick organic layer, and high aspect ratio patterns are obtained.