Sustainability of Atomic Layer Deposition Nanotechnology

Sustainability performance of atomic layer deposition (ALD) is significant because of ALD’s high energy consumption, toxic chemical and nano-particle emissions. This project is conducted systematically using both experimentation and modeling on ALD of Al₂O₃ process. Specific energy consumption is obtained around 1.54×10¹² J/kg, increasing with temperature and purging time. Thermodynamics and kinetics inside ALD chamber are simulated by Lattice Boltzmann Method and 3D transient numerical models. About 90% of precursors are found wasted during experimental analysis. 2×10⁴- 8×10⁴ nano-particles (<100 nm) and about 0.5 cm³ of CH₄ (25 °C, 1 atm) emissions are generated each cycle, while nano-particle emissions decrease with increase of purging time and gas emissions. The results would be useful for ALD system designers and technology developers to improve ALD process efficiency, minimize its environmental emissions and reduce risk of exposure.