Area-Selective\nMolecular Layer Deposition of Alucone\non Photoresist for Enhanced Pattern Transfer

Multilayer mask dry etching is commonly used for pattern\ntransfer\non industrial lines to reduce the semiconductor component size. One\nof the challenges is the need for improved photoresists (PRs) that\ncombine high resolution and etch selectivity with low complexity and\nmaterial cost. Here, an alternative masking approach using area-selective\nmolecular layer deposition (AS-MLD) has been shown to improve the\netch resistance and pattern transfer accuracy. This technology enables\nthe selective deposition of alucone into prepatterned PR areas or\na class of PRs rich in ester groups like poly(methyl methacrylate)\n(PMMA), avoiding the deposition on the silicon-based substrate. The\nAS-MLD minimizes feature size variation and reduces edge placement\nerrors. In this work, the mechanism of selective deposition of alucone\non PMMA and the inhibition mechanism on Si-based substrates were investigated\nin detail. The alucone-PMMA demonstrates considerable resistance to\nhigh-energy fluorine plasma etching. Compared to the original PMMA,\nthe etch resistance is improved by 85 times and the etch selectivity\nbetween alucone-PMMA-trimmed and SiON or SiO<sub>2</sub> can reach\nas high as 52 or 32, respectively. By improving film uniformity and\nthickness control, this method simplifies the manufacturing process,\nincreases production efficiency, and reduces costs. Our approach addresses\nthe urgent need for improved deposition selectivity and resolution\nin extreme ultraviolet (EUV) lithography and is an important step\ntoward achieving reliable and high-performance semiconductor devices.