Correlation of charge transport to intrinsic strain in silicon oxynitride and Si-rich silicon nitride thin films

Abstract

Poole–Frenkel emission in Si-rich nitride and silicon oxynitride thin films is studied in conjunction with compositional aspects of their elastic properties. For Si-rich nitrides varying in composition from SiN1.33 to SiN0.54, the Poole–Frenkel trap depth (ΦB) decreases from 1.08 to 0.52 eV as the intrinsic film strain (εi) decreases from 0.0036 to −0.0016. For oxynitrides varying in composition from SiN1.33 to SiO1.49N0.35, ΦB increases from 1.08 to 1.53 eV as εi decreases from 0.0036 to 0.0006. In both material systems, a direct correlation is observed between ΦB and εi. Compositionally induced strain relief as a mechanism for regulating ΦB is discussed.