Study of RLS trade-off mitigation utilizing an organotin-containing chemically amplified resist for high sensitivity patterning

EUV chemically amplified resists (CARs) have had big problems about a trade-off relationship between resolution, line width roughness (LWR), and sensitivity (RLS trade-off). The RLS trade-off problems have come to a head with the progress of pattern miniaturization. Moreover, etching durability of CARs are also gradually surfaced as an issue due to reducing film thickness to prevent pattern collapse. Previously, we proposed a novel chemically amplified resist platform that consists of polarity changer, cross linker and organotin compound. Polymers having triarylsulfonium cations, diarylmethanol and organotin compound as side chains were designed to realize a negative imaging property by using crosslinking through the acid catalytic etherification. It demonstrated RLS trade -off mitigation and low LER property by using two concentration of acetonitrile aqueous solution developer. Moreover, it could be observed two or threefold sensitization by using a UV flood exposure after EB lithography process applying new sulfonium cation structure which can be converted to UV absorbing structure by acid catalytic reaction.