Photo-enhanced negative differential resistance and photo-accelerated time-dependent dielectric breakdown in thin nitride-oxide dielectric film

Photo-enhanced negative differential resistance (NDR) and photo-accelerated time-dependent dielectric breakdown (TDDB) were observed in thin nitride-o xide (N-O) dielectric film biased with gate negative under tungsten lamp il lumination. The photo-induced leakage current and photo-accelerated TDDB sh ow dramatic asymmetry under negative and positive gate bias with constant p hoto-illumination. Our experiments suggest a unique current conduction mech anism in this nitride thin film. A two-carrier conduction induced positive feedback transport process under negative gate bias, and a two-carrier cond uction induced self-limiting transport process under positive gate bias are proposed to qualitatively explain the experimental data. The nitride thin film device possessing a light-enhanced NDR can be employed to develop Si-b ased optoelectronic devices such as switching and logic control. (C) 2001 A merican Institute of Physics.