New Amorphous Fluoropolymers of Tetrafluoroethylene with Fluorinated and Non-Fluorinated Tricyclononenes. Semiconductor Photoresists for Imaging at 157 and 193 nm

Abstract

Twenty-two tricyclo[4.2.1.0 2,5 ]non-7-ene (TCN) or 3-oxatricyclononene monomers, having fluorinated or nonfluorinated substituents on the four-membered rings, were prepared by cycloaddition reactions of functionalized olefins with norbornadiene or quadricyclane. Radical polymerizations with tetrafluoroethylene (TFE) and/or TFE and acrylates provided amorphous polymers with high solubility in standard organic solvents. The TFE/TCN dipolymers typically have glass transition temperatures of over 200°C, substantially higher than TFE copolymers with norbornene. Perfluoroalkyl sulfonyl fluoride groups can be incorporated in the side chains of the TCN monomers giving soluble copolymers. Polymers which also incorporated acrylate monomers were prepared using a semibatch process to control composition. Selected polymers incorporating tertiary alkyl ester groups from the TCN monomer or acrylates have shown good image formation when compounded with a photoacid generator, imaged with 157 or 193 nm light, and developed using aqueous base.

Synthesis of Narrow Molecular Weight Distribution Copolymers for ArF Photoresist Materials by Nitroxide Mediated Polymerization

“…We examined three other controlling comonomers for different reasons. PFS was studied here because fluorinated polymers have been shown to be good candidates for both 157 and 193 nm photoresists due to their low absorption, good etch resistance properties, and high hydrophobicity . Moderately narrow molecular weight distributions were achieved by adding around 5 mol% PFS in the feed.…”

Synthesis of Narrow Molecular Weight Distribution Norbornene-Lactone Functionalized Polymers by Nitroxide-Mediated Polymerization: Candidates for 193-nm Photoresist Materials

“…P-acetoxystyrene (AcOST), which has been employed in the past as a key component in 248-nm photoresists [68], exhibited the best controlling ability based on the lowest dispersity ( � � ⁄ ~ 1.29) at a concentration as low as 5 mol% in the feed. Pentafluorostyrene (PFS), also offering relatively good control ( � � ⁄ ~ 1.47 and 1.31 for 5 and 10 mol% in the feed, respectively), is of interest, because fluorinated polymers have been shown to be good candidates for both 157-nm and 193-nm photoresists, due to their low absorption, good etch resistance properties [69][70][71][72][73] and high hydrophobicity [74,75], which is especially important in immersion lithography. 2-vinyl naphthalene (VN) was also an effective co-monomer in being able to produce copolymers with low dispersities ( � � ⁄~ 1.3) with as low as 5 mol% in the feed.…”

Immersion Lithography: Photomask and Wafer-Level Materials

“…Ideally, the topcoat would dissolve in the same aqueous base developer (TMAH) used in the resist development step, but some topcoat versions were designed for nonaqueous solvent development, which adds an extra processing step. Many topcoats incorporate fluorinecontaining functional groups for their increased hydrophobicity, as well as the same compound 112 French · Tran types used effectively for absorbance reduction in 157-nm technology (88,(96)(97)(98)(99)(100)(101). These fluoropolymers have also been used in water immersion resist materials-either as additives to current 193-nm materials or as block copolymers (102)(103)(104).…”