Catalyzed selective atomic layer deposition of SiO2 on amorphous carbon via silicon blocking by alkyltrichlorosilane self-assembled monolayers

초록

As atomic-scale patterning becomes increasingly critical in advanced semiconductor processing, area-selective atomic layer deposition (AS-ALD) has emerged as a key nanofabrication strategy, mitigating the alignment limitations associated with conventional top-down lithography. In this study, we report a methodology for achieving selective deposition of SiO2 films on amorphous carbon (a-C) surfaces while suppressing growth on silicon (Si) surfaces using alkyltrichlorosilane inhibitor molecules. Conventional AS-ALD of SiO2 films frequently relies on highly reactive oxidants to address the limited reactivity of Si precursors at low temperatures, which often compromise inhibitor stability, resulting in reduced deposition selectivity. To address this limitation, we employ a catalyzed SiO2 ALD process using a pyridine catalyst, enabling SiO2 film growth with a mild H2O reactant at a low temperature of 100 °C. Comparison of inhibitors with different alkyl chain lengths revealed that octadecyltrichlorosilane (ODTS) forms the most robust inhibitor layer on Si substrates, attributable to its longer alkyl chain and improved molecular packing. Integrating chemoselective ODTS adsorption with the pyridine-catalyzed SiO2 ALD process enabled selective growth of 5 nm-thick SiO2 films exclusively on a-C surfaces. This approach provides a promising pathway toward robust and highly selective AS-ALD strategies. © 2026 Elsevier B.V.

키워드