Low‐Temperature Dual‐Material Area‐Selective Deposition: Molybdenum Hexafluoride‐Mediated SiO2 Fluorination/Passivation for Self‐Aligned Molybdenum/Metal Oxide Nanoribbons

Abstract Area‐selective deposition (ASD) is a forefront nanopatterning technique gaining substantial attention in the semiconductor industry. While current research primarily addresses single‐material ASD, exploring multi‐material ASD is essential for mitigating complexity in advanced nanopatterning. This study describes molybdenum hexafluoride (MoF 6 )‐mediated fluorination/passivation of the hydroxylated SiO 2 (SiO 2 ‒OH) at 250 °C as a new method to pacify nucleation during subsequent ZnO and TiO 2 atomic layer deposition (ALD). In contrast, Al 2 O 3 ALD is not passivated on the fluorinated SiO 2 (SiO 2 ‒F). The study further shows that Mo ALD using MoF 6 and silane (1 wt% SiH 4 in Ar) selectively proceeds on hydrogen‐terminated Si (Si‒H), whereas SiO 2 ‒OH becomes fluorine‐passivated without observable Mo deposition. This enables subsequent ZnO and TiO 2 ASD on Mo versus SiO 2 ‒F, as confirmed by X‐ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and scanning transmission electron microscopy (STEM). Proposed growth and inhibition mechanisms highlight the importance of the metal oxide precursor in achieving selectivity. Taken together, self‐aligned Mo/ZnO and Mo/TiO 2 nanoribbons are demonstrated on coplanar nanoscale Si‒H/SiO 2 ‒OH patterns by sequentially integrating two individual ASD processes: 1) Mo ASD on Si‒H versus SiO 2 ‒OH; and 2) ZnO or TiO 2 ASD on Mo versus SiO 2 ‒F. This work highlights the potential for this approach in new ASD systems.