Performance Improvement of ${\rm HfO}_{2}/{\rm SrTiO}_{3}$ Hetero-Oxide Transistors Using Argon Bombardment

An effective interface engineering method is developed to improve performance of SrTiO₃-based hetero-oxide transistors. HfO₂/SrTiO₃ hetero-oxide transistors made on argon ions bombarded SrTiO₃ surfaces show eight times increase in drive currents and more than five times increase in mobility when compared with the un-bombarded HfO₂/SrTiO₃ transistors. The improvement is attributed to the Fermi-level shift as the results of the bombardment. These HfO₂/SrTiO₃-based nMOSFETs show field-effect electron mobility up to 4.2 cm²/Vs, which is among the best results ever reported.