Light-Induced Electron Spin Resonance in Gate-Quality Nitrogen-Rich Amorphous Silicon Nitride: Photo-Production and Photo-Bleaching

ABSTRACTElectron spin resonance spectroscopy is used to monitor the light-induced, paramagnetic (neutral) defect density in gate-quality nitrogen-rich hydrogenated amorphous silicon nitride (a-SiN1.6:H) thin films. A new phenomenon has been observed in which the light-induced electron spin resonance (LESR) signal can be reduced (photo-bleached) by re-illuminating with monochromatic light. The extent to which the LESR signal is bleached depends strongly upon the incident photon energy used for re-illumination. Photo-bleaching as well as the photo-production of the LESR signal follow a stretched exponential dependence upon illumination time.