Improvement of dual insolubilization resist performance through the incorporation of various functional units

The acid diffusion in chemically amplified resists (a current standard resist for semiconductor device manufacturing) is a significant concern in the development of highly resolving resists. However, non-chemically amplified resists (non- CARs) are generally less sensitive to radiation than CARs due to lack of amplification mechanism. Recently, a negativetype non-CAR resist utilizing polarity change and radical crosslinking (a dual insolubilization resist) was proposed. In this study, an acid reactive compound was introduced into the organotin-containing dual insolubilization resists to improve their sensitivity. The synthesized resists were composed of triarylsulfonium cations as a polarity changer and radical generator, 2,2,2-trisubstituted acetophenone as a radical generator, triphenyl(4-vinylphenyl)stannane (TPSnSt) as an EUV absorption enhancer and a quencher, and 4-[(2,4-Dimethoxyphenyl)hydroxymethyl]phenylmethacrylate (ARMA) as a polymer-bound acid-reactive unit. By the incorporation of ARMA, the sensitivity to extreme ultraviolet (EUV) radiation was increased by 2.4 times (the exposure dose for insolubilization was decreased by approximately 60%). The sensitivity enhancement is considered to have been caused by the acid catalytic etherification of ARMA through dimerization and/or with 2,2,2-trisubstituted acetophenone units.