Conduction Mechanism in SrTiO3-Based Field-Effect Transistors

In this brief, we find that the previously reported performance improvement of HfO₂/SrTiO₃ devices after argon bombardment may be attributed to the decrease of interface traps. With the greatly reduced interface trap density, the HfO₂/SrTiO₃ device after argon bombardment shows remarkable reduction of turn-ON voltage shift with decreasing temperature, which is in contrast with the unbombarded HfO₂/SrTiO₃ device. Though HfO₂/SrTiO₃ devices behave like conventional transistors, Al₂O₃/SrTiO₃ devices show very different linear transfer characteristics, which may be due to the high density of shallow donor states near the Al₂O₃/SrTiO₃ interface. The exhibited SrTiO₃-based device characteristics are studied by experiments and simulations. The simulations with drift-diffusion model reproduce the experimental results.