Conduction Mechanism in SrTiO3-Based Field-Effect Transistors

In this brief, we find that the previously reported performance improvement of HfO
₂
/SrTiO
₃
devices after argon bombardment may be attributed to the decrease of interface traps. With the greatly reduced interface trap density, the HfO
₂
/SrTiO
₃
device after argon bombardment shows remarkable reduction of turn-ON voltage shift with decreasing temperature, which is in contrast with the unbombarded HfO
₂
/SrTiO
₃
device. Though HfO
₂
/SrTiO
₃
devices behave like conventional transistors, Al
₂
O
₃
/SrTiO
₃
devices show very different linear transfer characteristics, which may be due to the high density of shallow donor states near the Al
₂
O
₃
/SrTiO
₃
interface. The exhibited SrTiO
₃
-based device characteristics are studied by experiments and simulations. The simulations with drift-diffusion model reproduce the experimental results.