Field effect transistors based on BaSnO$_{3}$ with AlO$_{\mathrm{x}}$ and HfO$_{\mathrm{x}}$ gate oxides

La-doped BaSnO$_{3}$ (BLSO) is a transparent perovskite oxide semiconductor with high electron mobility and excellent oxygen stability. We fabricated n-type field effect transistors (FETs) on undoped BaSnO$_{3}$ (BSO) buffer layers on SrTiO$_{3}$ (STO) substrates using BLSO as the semiconducting channels and amorphous AlO$_{\mathrm{x}}$ and HfO$_{\mathrm{x}}$ as the gate insulators. BSO buffer layers and BLSO channels were grown by pulsed laser deposition, while the AlO$_{\mathrm{x}}$ and HfO$_{\mathrm{x}}$ gate insulators were grown by atomic layer deposition (ALD). Sn:In$_{2}$O$_{\mathrm{3}}$ (ITO) was used as the source, the drain and the gate electrodes. At room temperature, we achieved the field effect mobility value of 17.8 cm$^{2}$/Vs for the AlO$_{\mathrm{x}}$ FET and 19.2 cm$^{2}$/Vs for the HfO$_{\mathrm{x}}$ FET. The subthreshold swing was measured to be 3.2 V/dec for the AlO$_{\mathrm{x}}$ FET and 1.2 V/dec for the HfO$_{\mathrm{x}}$ FET.