Oxide-trap-induced instability in GIDL of thermally nitrided-oxide N-MOSFET's under stress

Abstract

Some holes created from band-to-band (B-B) tunneling in the deep-depletion region of the drain can be injected into the gate oxide and reduce the vertical field there. As a result, gate-induced drain leakage (GIDL) current decreases. This kind of hot-hole injection depends on the voltage difference between the drain and gate, due to nitridation-induced lowering of the barrier height for hole injection at the SiO2/Si interface. The subsequent hot-electron injection can neutralize these trapped holes, and make the GIDL current recover, and even increase beyond its original value. Since the trapped charges also affect the lateral field, the observed change in the ratio of substrate to source currents further confirms the proposed mechanism for the GIDL degradation and recovery behavior.