A negative working photosensitive polyimide based on poly(hydroxyimide) (PHI), 2,6-bis(hydroxymethyl)-4-methylphenol (BHMP) as cross-linker, and photoacid generator diphenyliodonium 9,10-dimethoxyanthracene-2-sulfonate (DIAS) has been developed. The PHI was prepared by the ring-opening polyaddition of 4,4‘-hexafluoroisopropylidenebis(phthalic anhydride) and 4,4‘-diamino-4‘‘-hydroxytriphenylmethane, followed by thermal cyclization in refluxing xylene. The PHI film showed excellent transparency to UV light. The photosensitive polyimide containing 70 wt % PHI, 20 wt % BHMP, and 10 wt % DIAS showed a sensitivity of 70 mJ/cm2 and a contrast of 3.8 when it was exposed to 365 nm light and postbaked at 120 °C, followed by developing with a 2.5% aqueous tetramethylammonium hydroxide solution at 40 °C. The mechanistic study on the formation of images is also discussed.

No abstract

A negative working photoresist based on calix[4]resorcinarene, 4,4′-methylenebis[2,6-bis(hydroxymethyl)phenol] (MBHP) as a cross-linker, and a photoacid generator, diphenyliodonium 9,10-dimethoxyanthracene-2-sulfonate (DIAS), has been developed. A clear negative pattern was obtained when it was exposed to 365 nm UV light and postbaked at 130 °C, followed by developing with a 0.5% aqueous tetramethylammonium hydroxide solution at room temperature.

Calix[4]resorcinarenes were prepared by the condensation of resorcinol and aldehydes (acetaldehyde, benzaldehyde, and 4-isopropylbenzaldehyde), and two isomers, C 4v (ccc) and C 2v (ctt), were separated by fractional crystallization. The products were characterized by NMR and FTIR, and their dissolution rate in aqueous base was measured. The eight hydroxyl groups of the calix[4]resorcinarenes were protected with acid labile t-butoxycarbonyl and t-butoxycarbonylmethyl. The protected calixarenes were thoroughly characterized by differential scanning calorimetry, FTIR, and variable-temperature 1H and 13C NMR. Their interaction with 4-isopropylphenol through hydrogen bonding was investigated by 13C NMR and correlated with their inhibition effect of dissolution of poly(4-hydroxystyrene-co-t-butyl acrylate) in an aqueous base, as studied by quartz crystal microbalance. Finally, the protected calixarenes were employed as a dissolution inhibitor of polyhydroxystyrene-based deep UV and electron beam chemical amplification resists to improve their contrast and performance.