Silicon nitride from microwave plasma: fabrication and characterization

Abstract

Plasma silicon nitride (P-SiN) films were prepared from SiH4–NH3 mixtures and from ternary mixtures with Ar or N2 in a large-volume microwave plasma apparatus, at substrate temperatures Ts ranging from ambient to 250 °C. Under otherwise nominally identical fabrication conditions, deposition rates were 10 to 25 times greater than those reported by others for radio-or audio-frequency plasmas. Based on film compositions determined by elastic recoil detection, and measurements of such properties as density, refractive index, etch rate in dilute HF, and the moisture permeation coefficient, our best P-SiN films (produced at Ts ≥ 200 °C) were very similar to those reported in the literature.