"Three-Color" Chemical Selectivity between Oxide, Nitride, and Silicon: Area-Selective Deposition of Metal Oxide and Polymer on SiN and Si-H versus SiO2.

Area-selective deposition (ASD) is an appealing bottom-up nanopatterning technique for semiconducting devices, but its capabilities are typically limited to growth and nongrowth surfaces with significantly different chemical properties. Moreover, few studies explore ASD on "multicolor" substrates containing more than two materials. Unlocking the full potential of ASD requires new methods compatible with chemically similar surfaces, such as SiO2 and SiN. It is shown that exposing nanoscale patterns of SiO2 and SiN to MoF6 at 200 °C passivates SiO2 but allows chemical vapor deposition of polypyrrole and atomic layer deposition of TiO2 on adjacent SiN. Moreover, using three-color substrates with exposed Si-H, SiO2, and SiN, transmission electron microscopy shows that one dose of MoF6 is sufficient to achieve > 9 nm of TiO2 ASD with S ≳ 0.926 on treated Si-H and SiN versus SiO2. A mechanism for MoF6-induced passivation is proposed, involving F transfer and removal of surface -OH groups. It is hypothesized that amine groups remaining on the SiN after MoF6 subsequently hydrolyze, allowing selective growth on the fluorinated SiN with limited deposition on fluorinated SiO2. These findings provide new insight for advanced ASD and other atomic scale processes.