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 SrTiO 3 -based hetero-oxide transistors. HfO 2 /SrTiO 3 hetero-oxide transistors made on argon ions bombarded SrTiO 3 surfaces show eight times increase in drive currents and more than five times increase in mobility when compared with the un-bombarded HfO 2 /SrTiO 3 transistors. The improvement is attributed to the Fermi-level shift as the results of the bombardment. These HfO 2 /SrTiO 3 -based nMOSFETs show field-effect electron mobility up to 4.2 cm 2 /Vs, which is among the best results ever reported.