Single Rare-Earth Ion Doped Tin-Oxo Nanocluster Photoresists for High-Resolution Extreme Ultraviolet Lithography.

Rare-earth (RE) metals are known as industrial vitamins and show significant regulatory effects in many fields. In this work, we first demonstrated that the vitamin effect of RE metals can also be applied to extreme ultraviolet (EUV) lithography. Using a SnRE oxo cluster as the universal platform, different individual RE metal ions were successfully doped to obtain a series of isomorphic heterometallic clusters (RE = Y, Sm, Eu, Ho, Er). Lithography experiments have shown that the doped RE ions displayed a significant influence on technical parameters. As a result, an electron-beam lithography (EBL) line width of 11.95 nm was achieved by SnEr, and an EUV lithography critical dimension (CD) of 15.90 nm was obtained by SnHo under an exposure dose of 52.64 mJ/cm. These findings expand the applications of rare earths in high-precision semiconductor manufacturing and provide a new strategy for the development of high-resolution EUV photoresists.