Reduction of persistent photoconduction in Ge-Ga-In-O semiconductors by the incorporation of nitrogen

Abstract

The effect of nitrogen incorporation in Ge-Ga-In-O (GGIO) semiconductors was investigated with respect to persistent photoconduction (PPC) and the associated thin-film transistor stability under negative bias illumination stress (NBIS). As the nitrogen partial pressure [pN₂ - N₂/(Ar + O₂ + N₂)] was increased from 0% to 40% during the reactive sputter growth of GGIO layers, the PPC phenomenon became less pronounced and higher device stability under NBIS was observed. X-ray photoelectron spectroscopy analyses suggest that the concentration of light-sensitive oxygen vacant sites in the GGIO semiconductors decreases as a result of nitrogen incorporation, hence the reduced PPC and higher device stability under NBIS.