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The main issue for developing EUV resist is to satisfy th e ITRS tar get of sensitivity, line edge roughness(LER), and resolution simultaneously . Howe ver, Resist resea rchers have dif ficulty in EUV resist development because they are tradeoff relationships each other. Among them, LER is cl osely related t o acid diffusion length of photo acid generator.Researchers have tried to accomplish uniform distribution and diffusion minimization of PAG in photoresist film in order to improve LER. They are mainly using two kinds of method for PAG introduction for uniform distribution and diffusion minimization. One i s u se of sulfonium sal ts ha ving ultra bulky ani on o r cat ion for t he aci d diffusion su ppression, t he other is direct incorporation of the PAG into the polymer backbone. In that regard, we have pursued development of a variety of 193nm and E UV CARs that contain photoacid generator(PAG) units covalently bonded directly to the resin polymer backbone. Whe n we consider pol ymer bound PAG, there can b e anionic pol ymer bound PAG resi st, cationic polymer bound PAG resist and n onionic po lymer bound resist. In this w ork, w e will d iscuss d iffusion length and lin e edge roughness(LER) of t hese polymers. Acid di ffusion l ength(Ld) an d diffusion c oefficient(D) were cal culated by according to t he m odified Fi ck,s e quation. As a result of this m easurements we kne w that diffusion l ength of general PAG use as ArF photoresist composition was ranged from thousands of nm to ten of nm and PAG diffusion length having bulky a nion a nd cat ion i s was wi thin a t en nm. In case of ani onic p olymer bo und PAG, aci d diffusion l ength showed under 10nm.Extreme Ultraviolet (EUV) Lithography II, edited by Bruno M. La Fontaine, Patrick P. Naulleau, Proc. of SPIE Vol. 7969, 79692N · © 2011 SPIE · CCC code: 0277-786X/11/$18 ·

A photoacid generator (PAG) is a component of chemical amplification photoresists (CAR). The most widely used PAG in CAR system is triphenyl onium salt which is well known to one of the best leaving groups from various radiation. Acid diffusion influences resist characteristics in area such as resolution and linewidth control. The structure of the hydrophilic PAG was designed to restrict acid diffusion within the photoresist. Acid amplification was suppressed by the hydroxyl group-acid interaction. Novel PAGs with functional groups were synthesized and characterized. Poly(GMA-co-MMA) was synthesized with a combination of crosslinkable glycidyl methacrylate (GMA) and highly refractive methyl methacrylate (MMA). The synthesized polymers were confirmed by NMR and FT-IR, and their thermal properties were studied using TGA and DSC. The resists were evaluated as a positive type resist for ArF lithography. PAGs exhibited good acid generation efficiency with controlled acid diffusion. We found that the energy latitude property of the photoresist was improved with hydroxyl-PAG.