Acid formation and deprotection reaction by novel sulfonates in a chemical amplification positive photoresist

A new simple method was developed to estimate the diffusion range of photogenerated acid in chemical amplification resist systems. The acid mobility was investigated for various process conditions. It was found that prebake and post-exposure-bake conditions have strong influence on the mobility of acid. The diffusion range of acid is much larger than values estimated from the catalytic volume. No acid diffusion could be detected at room temperature over a period of 2 days. Acid from an opium salt acid generator showed a stronger diffusion than acid from a methanesulfonic acid ester.

“…The synthesis of the sulfonic acid ester McSB has been described previously [3,4]. Onium salt acid generators were synthesized according to the literature [5].…”

Section: Methodsmentioning

confidence: 99%

Section: Acid Diffusion At Room Temperaturementioning

confidence: 97%

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Diffusion of photogenerated acid in chemical amplification positive deep UV resists.

Schlegel

Ueno

Hayashi

et al. 1991

“…[16] In the course of this study, it was shown that alkylsulfonates can act as an acid generator in deep-UV region and the acid generating reaction is based on the sensitization by novolak resin. [17,18] …”

Section: Positive Deep-uv Resistsmentioning

confidence: 99%

Chemical amplification resists for future lithography.

Ueno

Shiraishi

Uchino

et al. 1994

Self Cite

The technologies for future lithography have been proposed, such as i-line phase-shifting lithography, deep-UV lithography and electron beam lithography. We have proposed several types of chemical amplification resist systems for future lithography. These are based on the change in dissolution rate by acid catalyzed reaction for aqueous development: dissolution inhibitor to dissolution promoter for positive resists and the reverse for negative resist. Deprotection reaction of tetrahydropyranyl protected poly (hydroxystyrene) is used for positive resists. Silanol condensation reaction by acid catalyzed reaction was applied to negative resists. Pinacol rearrangement, etherification and intramolecular dehydration of carbinols can also be used for negative resists.

“…The acid-labile, t-BOC protected dissolution inhibitors in the form of tert-butyl (t-Bu) carbonate or t-Bu ester derived from phenol or benzoic acid functional groups were successfully applied to the three-component positive resist system as follows: t-Bu naphthalene-2-carboxylate and 2-(t-BOC-oxy)naphthalene [8], t-Bu cholate [4], 2,2-bis[4-(t-BOC-oxy)phenyl]propane [9,10], di-t-Bu isophthalate [11], and 2,2-bis[4-(t-BOC-methoxy)phenyl]propane [12]. Other acid-labile compounds such as acetals and prthoesters were also used in the formulations of highly sensitive positive resists [3].…”

Section: Introductionmentioning

confidence: 99%

A new chemical amplification resist system based on novolac and t-BOC protected phosphazene as a dissolution inhibitor.

Ahn

Kang

Kim

et al. 1992

t-BOC protected hexakis(4-t-BOC-phenoxy)cyclotriphosphazene, TBP, was synthesized from a semiinorganic phosphazene compound and its acid-catalyzed thermal deprotection was utilized in the design of a three-component positive resist system based on the combined principles of chemical amplification and dissolution inhibition. The new resist system, PTPNS(NRI TBP/PAG), is formulated with novolac resin (NR), TBP and a photoacid generator (PAG). The dissolution characteristics of PTPNS in alkaline development are ideally suited for application to positive type resists which are based on a dissolution inhibition mechanism. The t-BOC protected TBP of the PTPNS resist system effectively acts as an acid-labile dissolution inhibitor of novolac resin when TBP concentration is more than 10 % by weight. As a representative, PTPNS(100/15/5) (by weight parts) exhibited high sensitivity in the range of 20 to 25 mJ/cm2 with contrast of 5 after exposure at 250nm light and PEB treatment at 100 to 130°C. Appropriately formulated PTPNS resist rendered positive-tone patterns down to sub-half micron with high sensitivity when the resist was exposed to KrF excimer laser or electron beam and developed with 2.38 wt% tetramethylamonium hydroxide solution.