Improvement of Post-Exposure Delay Stability in Alicyclic ArF Excimer Photoresists

Abstract

This paper reports work toward designing environmentally stable alicyclic polymerbased photoresists for ArF excimer laser lithography. A design concept for improving postexposure delay stability is suggested in this paper. The polymers described here were prepared from dinorbornene derivatives and maleic anhydride by free radical polymerization. The relationship among polymer structure, glass transition temperature (Tg) and post-exposure delay stability was studied. This new polymer design offers a pathway towards good post-exposure delay stability while maintaining high resolution.

Microlithographic Assessment of a Novel Family of Transparent and Etch-Resistant Chemically Amplified 193-nm Resists Based on Cyclopolymers

“…Preliminary evaluation of several photoacid generators 9 in related photoresists showed that best results in terms of resolution and sensitivity were obtained with triphenylsulfonium nonafluorobutanesulfonate 5b. The fluoroalkyl sulfonic acid that is generated photochemically has been shown to have little or no volatility and therefore provides best results in avoiding unwanted webbing and “T-top” formation in the resulting images …”

“…Since added hydrophilicity appeared desirable, the copolymers with maleic anhydride were then evaluated. Maleic anhydride has become a popular choice as a polar comonomer in many 193-nm polymer resist systems, because of its ability to enhance the wettability and the adhesion to silicon substrates of the corresponding resist formulations. ,, Resists containing copolymer 4 showed excellent resolution down to 0.18 μm 1:1 line/space (L/S) features, but they were still too hydrophobic, as they had to be developed by full immersion of the wafer in the aqueous developer. As can be seen in Figure , this led to pattern collapse during the develop/rinse step.…”

Organic imaging materials: a view of the future

“…36 Figure 9 shows scanning electron micrographs of resist features produced using this 193 nm system. A number of improvements and refinements in this basic resist design have been reported, 38,39 and it is likely that commercial photoresists based on derivatives of this basic system design will support 193 nm production.…”

Solid-Phase Synthesis of Tris-Benzamides as α-Helix Mimetics

“…In addition to the hydrophobic functional groups, hydrophilic ones like 3-carboxypropyl (CPr) and 4-aminobutyl (ABu) groups were also introduced as R 2 to represent the side chains of Glu and Lys, respectively. The optimized reaction condition for less reactive alkyl halides allowed to the preparation of chemset 8b { 5 − 6 } in 78% and 84% purities, respectively (entry 13 and 14) with t -butyl 4-bromobutyrate and 4-( t -butoxycarbonylamino)butyl tosylate . The t -butyl protecting groups of the hydrophilic substituents can be easily removed with TFA at high concentrations at the end of the synthesis.…”