Area Selective Deposition of Ru on W/SiO2 Nanopatterns via Sequential Reactant Dosing and Thermal Defect Correction

Abstract

Area selective deposition (ASD) of ruthenium offers a promising approach to fabricate ultrathin, continuous, and low-resistivity films for metallic interconnection in various microelectronic applications. This study employs an advanced sequential reactant dosing combined with a thermal defect correction strategy to obtain high selectivity and film quality. Through the adoption of sequential reactant dosing, chemisorption becomes the prevailing mechanism and effectively prevents excess physical adsorption. This method not only enhances coverage but also reduces steric hindrance from occupying the neighboring active sites, aligning with Kinetic Monte Carlo simulations. The defect correction process benefits from a low temperature and inert atmosphere, which curtails nanoparticle coarsening due to Ostwald ripening. Additionally, reducing particle size via sequential dosing facilitates defect migration and increases selectivity. The robust ASD technique is successfully applied to W/SiO₂ nanopatterns for metal interconnects, achieving ∼5 nm Ru on tungsten while no detectable defects on SiO₂ areas, which offers an encouraging method for advanced semiconductor nodes.