Deposition selectivity on oxide versus metal surfaces via catalyzed atomic layer deposition of SiO2 and vapor-dosed phosphonic acid inhibitors

With the continued downscaling of devices toward sub-10 nm, area-selective atomic layer deposition (AS-ALD) has emerged as a groundbreaking bottom-up patterning technique, addressing misalignment challenges while enabling selective deposition on targeted areas with atomic-level precision. In this study, we present a strategy for achieving selective deposition of SiO₂ thin films through a pyridine-catalyzed ALD process, facilitated by vapor-dosed phosphonic acid (PA) self-assembled monolayers (SAMs) on metal versus dielectric surfaces. By utilizing a chemical vapor transport (CVT) process, a bulky PA inhibitor with a fluorocarbon terminal group was effectively vaporized, and unintended PA SAMs on dielectric surfaces were readily removed through a post-HF treatment, leading to AS-ALD of SiO₂ thin films exclusively on SiO₂ surfaces. As a results, SiO₂ film growth on PA SAM/HF-treated TiN surfaces was suppressed by up to 5 nm with mild H₂O reactants at a substrate temperature as low as 100 ℃. The proposed approach broadens the applicability of AS-ALD of SiO₂ thin films by ensuring the efficient incorporation of inhibitors during subsequent ALD processes.