Effect of N2O/SiH4 flow ratio on properties of SiOx thin films deposited by low-temperature remote plasma-enhanced chemical deposition

Silicon oxide (SiOx) layers were deposited on silicon and plastic substrates at a low substrate temperature of 100 °C by remote plasma-enhanced chemical deposition (RPE-CVD) using a combination of SiH4/N2 gases in N2O/Ar remote plasma. The deposition rate of the SiOx layers initially increased with increasing N2O/SiH4 flow ratio of 10 and then decreased with further increases. Under the current experimental conditions, gas-phase reactions leading to powder formation were minimized by increasing the N2O/SiH4 flow ratio at the reduced SiH4 flow rate of 10 sccm. The silicon oxide thin films became Si-rich with increasing N2O/SiH4 flow ratio. The leakage current of the SiOx layer was higher at the lower N2O/SiH4 flow ratio, which was attributed to the increased rate of gas-phase reactions leading to a film with a less dense structure.