Selective Surface Passivation for Ultrathin and Continuous Metallic Films via Atomic Layer Deposition

Abstract

The high surface energy of metals often drives the formation of isolated ultrathin islands of metal nuclei during film fabrication, which remains a significant challenge in achieving continuous, smooth metallic films. This study introduces an inhibitor-modified atomic layer deposition (ALD) strategy for producing ultrathin continuous Ir and Pt films on dielectric substrates. Aniline, which was used as the inhibitor, was exclusively adsorbed onto the metallic surface. The selective passivation of metal nuclei with aniline suppresses the lateral growth of existing nuclei while promoting the formation of new nuclei, enabling the formation of continuous films with thicknesses below 1 and 2.3 nm for Ir and Pt, respectively. Compared with conventional ALD, this approach significantly improved the surface smoothness and reduced the resistivity. Furthermore, this approach is particularly effective for precursors with substantial nucleation delays. This strategy offers an effective solution for fabricating ultrathin and smooth metallic films for emerging electronic devices.