Plasma-enhanced atomic layer deposition of silicon nitride thin films with different substrate biasing using Diiodosilane precursor

In this work, we report on Plasma-Enhanced Atomic Layer Deposition (PE-ALD) of SiN x films using Diiodosilane (DIS) precursor and N 2 -H 2 plasma. Systematic studies as a function of DIS dosing time, plasma duration, plasma composition and deposition temperature are investigated. The material properties have been studied using X-ray photoelectron spectroscopy (XPS), X-Ray Reflectometry (XRR), Atomic Force Microscopy (AFM) and High-Resolution Transmission Electron Microscopy (HR-TEM). The optimal deposition parameters for achieving high-quality SiN x with a high growth per cycle (GPC) are first determined. We show that DIS offers a wide temperature window for SiN x deposition starting from 110 °C up to 300 °C, paving the way for a large choice of SiN-based applications. The impact of substrate biasing on SiN x film deposition and properties is also investigated. We show that high ion energies during the nitridation step can cause surface damage and void formation, thus affecting the SiN x quality. Overall, these results highlight the importance of this novel precursor for growing SiN x using PE-ALD and the possible swapping of the material properties by fine control of the substrate biasing, which can help to go far beyond the existing SiN x limitations.