Reduction of photoleakage current in polycrystalline silicon thin-film transistor using NH3 plasma treatment on buffer layer

Abstract

The technology of polycrystalline silicon thin-film transistors (poly-Si TFTs) with low photoleakage current is developed in this work. The electrical characteristics of poly-Si TFTs under illumination were significantly improved employing the NH3 plasma treatment on the buffer layer, with no need for complicate device structure and additional masks. The trap states that originated from the plasma bombardment on the interface between the poly-Si layer and buffer oxide can effectively recombine the light-induced electron-hole pairs. The fewer residual electron-hole pairs lead to the lower photoleakage current and improved subthreshold swing, as well as maintaining good electrical characteristics in the dark sate. (C) 2008 American Institute of Physics.