A New Three-Component Photoresist Based on Calix[4]resorcinarene Derivative, a Cross-linker, and a Photo-acid Generator

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Abstract
Calix[4]resorcinarene (2,8,14,20-tetramethylcalix[4]arene-4,6,10,12,16,18,22,24-octol, abbrev. to C4-RA) derivative (4) having p-hydroxybenzyl groups on its exterior was prepared by the condensation of C4-RA and p-(allyloxy)benzyl bromide, followed by the cleavage of allyl groups with palladium catalyst and ammonium formate. Compound 4 having high transparency to UV-light above 300 nm was considered for a new resist matrix. A three-component photoresist consisting of 4, 2,6-bis(hydroxymethyl)-4-methylphenol (BHMP), and diphenyliodonium 9,10-dimethoxyanthracene-2-sulfonate (DIAS) showed a sensitivity of 19 mJ cm−2 (D1/2) and a contrast of 3.0 (γ1/2) when it was exposed to 365 nm light and post-exposure baked (PEB) at 110 °C for 5 min, followed by developing with a 0.2 wt% aqueous tetramethylammonium hydroxide (TMAH) solution. A fine negative image featuring 1 μm of minimum line and space patterns was observed on film of the photoresist exposed to 40 mJ cm−2 of UV-light at 365 nm with a scanning electron microscope.