In Situ Observation of β-Ga2O3 Schottky Diode Failure Under Forward Biasing Condition

In this article, we investigate defect nucleation leading to device degradation in beta-Ga2O3 Schottky barrier diodes by operating them inside a transmission electron microscope. Such in situ approach allows simultaneous visualization and quantitative device characterization, not possible with the current art of postmortem microscopy. High current density and associated mechanical and thermal fields are shown to induce different types of crystal defects, from vacancy cluster and stacking fault to microcrack generation prior to failure. These structural defects can act as traps for carrier and cause device failure at high biasing voltage. Fundamental insights on nucleation of these defects and their evolution are important from materials reliability and device design perspectives.