High mobility BaSnO3 films and field effect transistors on non-perovskite MgO substrate

Abstract

(Ba,La)SnO3 is a wide bandgap semiconducting perovskite oxide with high electron mobility and excellent oxygen stability. The carrier modulation of (Ba,La)SnO3 channel by field effect on perovskite SrTiO3 substrates has been demonstrated in the recent reports. Here we report that (Ba,La)SnO3 on non-perovskite MgO substrate can also exhibit a high electron mobility and excellent carrier modulation by field, an important step towards scaling up for wafer-size processing. We optimized the undoped buffer layer thickness and measured the transport properties as a function of the La doping. The maximum mobility is 97.2 cm2/Vs at 2.53×1020/cm3. The transmission electron microscope images show that the films are epitaxial with about 2×1011/cm2 threading dislocation density. The field effect device based on the (Ba,La)SnO3 channel on MgO substrates is modulated with a high mobility of 43.9 cm2/Vs and Ion/Ioff of about 3.0×107.