High mobility field effect transistor based on BaSnO3 with Al2O3 gate oxide

We fabricated an n-type accumulation-mode field effect transistor based on BaSnO3 transparent perovskite semiconductor, taking advantage of its high mobility and oxygen stability. We used the conventional metal-insulator-semiconductor structures: (In, Sn)(2)O-3 as the source, drain, and gate electrodes, Al2O3 as the gate insulator, and La-doped BaSnO3 as the semiconducting channel. The Al2O3 gate oxide was deposited by atomic layer deposition technique. At room temperature, we achieved the field effect mobility value of 17.8 cm(2)/Vs and the I-on/I-off ratio value higher than 10(5) for V-DS = 1V. These values are higher than those previously reported on other perovskite oxides, in spite of the large density of threading dislocations in the BaSnO3 on SrTiO3 substrates. However, a relatively large subthreshold swing value was found, which we attribute to the large density of charge traps in the Al2O3 as well as the threading dislocations. (C) 2014 AIP Publishing LLC.