Area-Selective Atomic Layer Deposition on Homogeneous Substrate for Next-Generation Electronic Devices

Area-selective atomic layer deposition (AS-ALD) has focused on controlling the promotion or blocking of precursor molecules on "heterogeneous" surfaces comprising different materials. This study proposes a new concept of AS-ALD on "homogeneous" surfaces comprising a single material. In this work, a homogeneous ZrO₂ substrate is selectively fluorinated using sulfur hexafluoride (SF₆) gas. The SF₆ decomposes and incorporates into oxygen vacancies in ZrO₂, forming F-terminated surface at grain boundaries (GBs). In the following step, the remaining hydroxyl-terminated ZrO₂ areas are blocked by a cyclopentadienyl ligand to prevent aluminum precursor adsorption. Density functional theory and Monte Carlo simulations show that selectively passivated GBs of ZrO₂ lead to the selective adsorption of ZrCp(NMe₂)₃ inhibitors. Selective growth of Al₂O₃ along GBs of ZrO₂ is observed by elemental mapping from transmission electron microscopy. Finally, GB-selective Al₂O₃ increases overalldielectric constant by 15.5% in ZrO₂/Al₂O₃/ZrO₂ stacks with no increase in leakage currents, showing that the GB-selective Al₂O₃ incorporation suffices to passivate leakage paths through ZrO₂ GBs. These findings provide fundamental guidelines for performing AS-ALD on homogeneous surfaces and highlight the potential of this approach for applications in next-generation electronic devices.