Kinetics of Interface State Generation Induced by Hot Carriers in N-Channel Polycrystalline Silicon Thin-Film Transistors

Abstract

Interface state creation, induced by hot hole injection, has been frequently observed in n-channel polysilicon thin-film transistors, when subjected to prolonged bias stress with negative gate biases. In this work we propose a new model for the kinetics of interface state formation, that closely links the interface state generation to the measured gate leakage current. The interface state generation mechanism appears to be driven by the recombination of hot holes (injected from the semiconductor active layer) with electrons (injected from the gate electrode). This model is shown to fit very well the time evolution of the interface states, as determined by the sheet conductance of the damaged region close to the drain.