Temperature dependence of conduction current in silicon oxynitride films grown by PECVD

摘要

Silicon oxynitride films with different nitrogen contents were deposited by plasma enhanced chemical vapor deposition. Electrical conduction current was found to be enhanced if the films were annealed at high temperatures. In order to investigate this reason, the temperature (T) dependence of conduction current density (J) was measured. It was found that the conduction current was found to be governed by the Poole-Frenkel effect and that the activation energy estimated from the J-T relation decreases with an increase in the annealing temperature. Electron spin resonance spectroscopy and Fourier-transform infrared spectroscopy revealed that hydrogen atoms present abundantly in the films terminate silicon-, nitrogen-, and oxygen-related dangling bonds. These atoms are detached by the annealing, resulting in the many localized states that enhance carrier transport.