Amorphous SiN:H dielectrics with low density of defects

Abstract

Amorphous SiN_x:H films were prepared by rf glow discharge (GD) of SiH₄‐N₂‐H₂ mixtures at 300 °C using a new decomposition technique. The optical gap E_g increases slowly with the ratio N₂/SiH₄ up to a critical gap E_gc of 2.5–3.0 eV, and then rapidly increases up to 5.3 eV. The spin density N_s from electron spin resonance of Si dangling bonds increases with N₂/SiH₄ until E_g reaches E_gc. Above E_gc, N_s rapidly decreases in contrast with that of conventional GD films, but in similarity to pyrolytic films. The slope B in Tauc equation for optical absorption corresponds well with N_s.