Defect-Hydrogen Interactions in Top-Anode Oxide Semiconductor Schottky Barrier Diode

As amorphous oxide semiconductors (AOSs) are hotly pursued for advanced displays, flexible electronics, optoelectronics, and neuromorphic systems, the AOS Schottky barrier diodes (SBDs) have been tried only using the mainstream amorphous InGaZnO (a-IGZO) and the conservative bottom-anode structure. To deepen the study on AOS SBDs, the more challenging top-anode SBD is developed in this work using a versatile but vulnerable AOS, amorphous InZnO (a-IZO). Unsurprisingly, the Schottky interface defects are seriously increased by the top-anode process and the defective a-IZO, which cannot be effectively passivated using the incumbent oxidizing treatments. The hydrogenation is proposed to considerably suppress these annoying interface defects and thus correspondingly reduces the large leakage current, while the hydrogen doping easily deteriorates a-IGZO SBD. The underlying mechanism of such distinction is revealed to be the tricky interactions between defect and hydrogen in AOSs. Based on the sophisticated utilization of such defect-hydrogen interplay, the a-IZO/a-IGZO stack is hydrogenated together to simultaneously realize a high-conductivity bulk and low-defect interface, noticeably enhancing the performance metrics. Such top-anode SBD based on hydrogenated multilayer AOSs successfully blazes a novel evolution path for AOS SBDs.