Plasma enhanced chemical vapour deposition of SiOxNy in an integrated distributed electron cyclotron resonance reactor

The deposition of silicon alloy thin films at room temperature is of increasing interest for various applications, such as functional, protective and optical coatings on polymers. In this work an integrated distributed electron cyclotron resonance (IDECR) high density plasma reactor is used for the deposition of SiOxNy thin films with variable optical properties. The reactor has planar geometry and is scalable for large area applications. Properties of material are analyzed with in situ UV-Visible ellipsometry, ex situ infrared transmission, RBS and ERDA measurements. Without substrate heating, dense, non-absorbing and low hydrogen content stoichiometric films of SiO2 and Si3N4 are grown from the mixture of SiH4, O-2 and N-2. Deposition rates are between 0.5 and 5 nm/s for Si3N4 and SiO2, respectively. By changing the nitrogen to oxygen gas flow ratio the refractive index (measured at 632.8 nm) can be smoothly and reproducibly tuned from 1.96 to 1.46. The correlation between material properties and plasma parameters indicates that the silane partial pressure influences the hydrogen incorporation into the silicon nitride films. (C) 1999 Elsevier Science B.V. All rights reserved.