We have investigated epitaxial BaHfO 3 as a high-k perovskite dielectric. From x-ray diffraction measurement, we confirmed the epitaxial growth of BaHfO 3 on BaSnO 3 and MgO. We measured optical and dielectric properties of the BaHfO 3 gate insulator; the optical bandgap, the dielectric constant, and the breakdown field. Furthermore, we fabricated a perovskite heterostructure field effect transistor using epitaxial BaHfO 3 as a gate insulator and La-doped BaSnO 3 as a channel layer on SrTiO 3 substrate. To reduce the threading dislocations and enhance the electrical properties of the channel, an undoped BaSnO 3 buffer layer was grown on SrTiO 3 substrates before the channel layer deposition. The device exhibited a field effect mobility value of 52.7 cm 2 V −1 s −1 , a I on /I off ratio higher than 10 7 , and a subthreshold swing value of 0.80 V dec −1 . We compare the device performances with those of other field effect transistors based on BaSnO 3 channels and different gate oxides.
All Science Journal Classification (ASJC) codes
- Materials Science(all)