A new photoresist materials for 157nm lithography-3: poly [2-hydroxy-3-pinanyl vinyl sulfonate-co-4-(1,1,1,3,3,3hexafluoro-2-hydroxypropyl)styrene]

Abstract

A new photoresist for 157 nm lithography on the basis of poly[(2-hydroxy-3-pinanyl vinyl sulfonate)-co-4-(1,1,1,3,3,3-hexafluoro-2-hydroxypropyl)styrene] [poly(VSO3Pina73-co HFISt27)] and triphenylsulfonium perfluoro-1-butanesulfonate (TPS-Nf) as a photoacid generator (PAG) has been developed. Poly(VSO3Pina-co-HFISt)s were prepared by free radical polymerization of VSO3Pina with HFISt. The photoresist consisting of poly(VSO3Pina73-co-HFISt27) and 4 wt% TPS-Nf showed a sensitivity of 10 mJ cm-2 and a contrast of 6, when it was exposed to 157 nm laser and developed with 0.6 wt% aqueous tetramethylammonium hydroxide (TMAH) solution at 25 °C. A fine positive image of 140 nm line and space patterns was printed in a film, which was exposed to 15 mJ cm-2 by a contact printed mode. The resist film showed an optical density (OD) value of 3.6 μm-1 at 157 nm wavelength.