The N2–SiH4rf glow‐discharge plasma has been analyzed by line‐of‐sight mass spectrometry of species impinging on the deposition electrode (including N atoms), and properties of SiNxHyfilms deposited from this plasma have been examined. At high rf power and low SiH4/N2gas ratio, most of the SiH4is consumed by reaction of SiHmradicals with N atoms at the film surface and becomes incorporated into the film. No Si–N precursor species are seen in the plasma. This is in contrast to the NH3–SiH4plasma, where the Si(NH2)3radical is the key gas‐phase precursor. If power is insufficient or SiH4flow is excessive, disilane is formed in the plasma. Under disilane‐free plasma conditions, films slightly N rich with no Si–H bonding and only 11 at. % H (as N–H) can be deposited at high rate (21 nm/min). The film tensile stress characteristic of the NH3process is absent in the N2process due to the absence of precursor chemical condensation beneath the growing surface. However, step coverage is much worse in the N2process due to the much higher sticking coefficients of the reactant radicals. The N2plasma chemistry is the same using 400 kHz or 13 MHz rf power, but compressive stress and H content are both higher at the lower frequency due to H+implantation.