Synthesis and Resist Sensitive Property of Iodine-Containing Materials using Extreme Ultraviolet (EUV) Exposure Tool

Abstract

We examined the synthesis, physical properties, and resist properties of various iodine-containing molecules and polymers as resist materials. By condensation reaction of 2,6-dimethylphenol (DMP) with 4-iodebenzaldehyde (IBA), 3,5-diiodesalicylaldehyde (DISA) and 4-hydroxy-3,5-diiodebenzaldehyde (HDIA), the corresponding iodine containing compounds DIPM, 2-DIPM, and 4-DIPM were synthesized. The reaction of these compounds with adamantyl bromo acetate, yielding corresponding compounds with adamanty ester groups DIPM-AD, 2-DIPM-AD, and 4-DIPM-AD. The polyaddition of 4-DIPM with divinyl ethers such as diethylene glycol divinyl ether (DGDE), 1,4-bis(allyloxymethyl)cyclohexane (BAC), 2,2'-bis(4-vinyloxyethoxyphenyl)perfluoropropane (BVFP) was investigated to give iodine containing hyperbranched polyacetals poly(4-DIPM-co-DGDE), poly(4-DIPM-co-BAC), poly(4-DIPM-co-BVFP). In the same way, tri(4-hydoroxyphenyl)methane (THM) was used instead of 4-DIPM, the corresponding hyperbranched polyacetals poly(THM-co-DGDE), poly(THM-co-BAC), and poly(THM-co-BVFP) were also synthesized. Almost all resist materials had good physical properties (solubility, film formation, high thermal stability,) and excellent thickness loss property. The resist sensitivity in the extreme ultraviolet (EUV) exposure tool showed that these resist materials were good candidate to offer higher resolution resist pattern, i.e., E0 = 7.0 mJ/cm2 for DIPM-AD, E0 = 7.0 mJ/cm2 for 2-DIPM-AD, E0 = 2.0 mJ/cm2 for 4-DIPM-AD, poly(THM-co-DGDE) and poly(THM-co-BAC), E0 = 1.0 mJ/cm2 for poly(4-DIPM-co-DGDE) and poly(4-DIPM-co- BVFP).