Ozone based high-temperature atomic layer deposition of SiO2 thin films.

In this paper, atomic layer deposition of SiO₂ thin films was investigated with Si₂Cl₆ and O₃/O₂ (400 g m⁻³). O₃/O₂ is not preferred for high-temperature (>400 °C) processes due to its lower decomposition temperature, especially in a furnace-type chamber. However, with Si oxidation test using a cold-wall chamber, we have demonstrated the reactivity of O₃/O₂ up to 800 °C in comparison with O₂ and H₂O. The ALD of SiO₂ films was examined at deposition temperatures from 500 °C to 700 °C. The growth rate at 600 °C was saturated to 0.03 nm/cycle with Si₂Cl₆ exposure over 1.2 × 10⁵ L. O₃/O₂ also showed ALD-like saturation behaviors for exposures over 2.4 × 10⁶ L. The ALD films deposited at 600 °C exhibited relatively smooth surface roughness (<0.18 nm) and low wet etch rate (1.6 nm min⁻¹, 500:1 HF) that are comparable with PECVD SiO₂ deposited at 250 °C and LPCVD SiO₂ deposited at 450 °C. [ABSTRACT FROM AUTHOR]