Study on dissolution behavior of polymer-bound and polymer-blended photo acid generator (PAG) resists by using quartz crystal microbalance (QCM) method

• The difference in swelling formation between KrF and EUV exposure was observed.
• The swelling of polymer-bound PAG is less than that of polymer-blended PAG.
• Polymer-bound PAG suppresses swelling very well and showed an excellent performance.

The requirements for the next generation resist materials are so challenging that it is indispensable for feasibility of EUV lithography to grasp basic chemistry of resist matrices in all stage. Under such circumstances, it is very important to know dissolution behavior of the resist film into alkaline developer though the dissolution of exposed area of resist films in alkaline developer to form a pattern is a complex reactive process. Therefore, the aqueous base development process is one of the most critical processes in EUV lithography. In this study, the influence of EUV and KrF exposure on the dissolution behavior of polymer-bound PAG and polymer-blended PAG was studied in detail using quartz crystal microbalance (QCM) methods. The difference in swelling formation between KrF and EUV exposure was observed. It is likely that difference of reaction mechanism induces the difference of these swelling. Also, it was observed that the swelling of polymer-bound PAG is less than that of polymer-blended PAG in both KrF and EUV exposure. This indicates that polymer-bound PAG suppresses swelling very well and showed an excellent performance. Actually, the developed polymer bound-PAG resist showed an excellent performance (half pitch 50 nm line and space pattern). Thus, polymer-bound PAG is one of the promising candidate for 16 nm EUV resist.

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