## Abstract

It is generally accepted that the charge transport in dielectrics is governed by coulombic trap ionization due to a barrier lowering in high electric fields (Frenkel effect). In this paper, the charge transport mechanism in Si _{3} N _{4} and nonstoichiometric silicon rich SiN _{x} is experimentally studied and quantitatively analyzed with five theoretical models: Frenkel model of Coulomb traps ionization, Hill-Adachi model of overlapping Coulomb traps, Shklovskii-Efros percolation model, Makram-Ebeid and Lannoo model of multiphonon isolated traps ionization and Nasyrov-Gritsenko model of phonon-assisted electron tunneling between nearby traps. It is shown that the charge transport in Si _{3} N _{4} and SiN _{x} is qualitatively described by Frenkel effect, but Frenkel effect predicts an enormously low attempt to escape factor value. The charge transport at traps energies W _{t} = 1.6 eV and W _{opt} = 3.2 eV in Si _{3} N _{4} and SiN _{x} can be described by an increase in traps concentration in the framework of Makram-Ebeid and Lannoo model and Nasyrov-Gritsenko model. The Makram-Ebeid and Lannoo model quantitatively describes the charge transport in Si _{3} N _{4} and SiN _{x} with low silicon enrichment. The charge transport in nonstoichiometric SiN _{x} with high silicon enrichment is well explained by Nasyrov-Gritsenko model.

Original language | English |
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Article number | 036304 |

Journal | Materials Research Express |

Volume | 6 |

Issue number | 3 |

DOIs | |

State | Published - 1 Mar 2019 |

## Keywords

- Charge transport
- percolation
- traps
- traps ionization