Leakage Current Reduction Using 350-nm Ultra-Violet Irradiation in P-Channel Polycrystalline-Silicon Thin-Film Transistors

We developed a novel technique to reduce the gate-induced drain leakage (GIDL) current by a simple method using the 350-nm ultraviolet (UV) irradiation at 300 W. The pinning GIDL current was reduced from 94% without any pinning, and the threshold voltage was shifted from -6 to -2 V after 1000 s. The mechanism of the GIDL current reduction is deeply investigated and confirmed by the density of states, drain activation energy (E
_a
), and extraction of grain-boundary traps (N
_t
). The density of acceptor-like states increases with the increase in UV exposure. The shift in Fermi level away from the valence band to the conduction band under the UV irradiation is the main proposed mechanism for the GIDL current reduction.