Atomic Layer Deposition of Epitaxial and Polycrystalline SnO₂ Films from the SnI₄/O₂ Precursor Combination

Abstract

Abstract Thin films of SnO 2 have been successfully deposited by atomic layer deposition (ALD) using the SnI 4 /O 2 precursor combination. Depositions were carried out in the temperature range 400–750 °C on SiO 2 /Si(100) and single‐crystalline α‐Al 2 O 3 (012) substrates. The films were found to grow as the tetragonal SnO 2 phase (cassiterite), polycrystalline on SiO 2 /Si(100), and epitaxial on the α‐Al 2 O 3 (012) substrates with the in‐plane orientation relationships [010] ∥ [100] and [10 $\bar 1$ ] ∥ [ $\bar 1$ $\bar 2$ 1] . In general the growth rate was high, changing from 0.10 nm cycle –1 at 500 °C to 0.12 nm cycle –1 at 750 °C for the α‐Al 2 O 3 (012) substrates, and from 0.04 nm cycle –1 at 400 °C to 0.24 nm cycle –1 at 750 °C for the SiO 2 /Si(100) substrates.