SrTiO3 films with different cation concentration were deposited on Si(001) substrates by oxide molecular beam epitaxy. An amorphous layer was observed at the interface whose thickness depends on the oxygen pressure ...SrTiO3 films with different cation concentration were deposited on Si(001) substrates by oxide molecular beam epitaxy. An amorphous layer was observed at the interface whose thickness depends on the oxygen pressure and the substrate temperature during growth. Although lowering the oxygen vacancy concentration in SrTiO3 led to better insulating performance as indi- cated by the lowered leakage current density of the heterostructure, the dielectric performance was deteriorated because of the thickened interracial layer that dominated the capacitance of SrTiO3/Si heterostructure. Instead of adjusting the oxygen vacan- cy concentration, we propose that controlling the film cation concentration is an effective way to tune the dielectric and insu- lating properties of SrTiO3/Si at the same time.展开更多
基金supported by the National Basic Research Program of China(Grant No.2012CB921700)the National Natural Science Foundation of China(Grant No.11225422)the US Natural Science Foundation(Grant No.DMR-1106070)
文摘SrTiO3 films with different cation concentration were deposited on Si(001) substrates by oxide molecular beam epitaxy. An amorphous layer was observed at the interface whose thickness depends on the oxygen pressure and the substrate temperature during growth. Although lowering the oxygen vacancy concentration in SrTiO3 led to better insulating performance as indi- cated by the lowered leakage current density of the heterostructure, the dielectric performance was deteriorated because of the thickened interracial layer that dominated the capacitance of SrTiO3/Si heterostructure. Instead of adjusting the oxygen vacan- cy concentration, we propose that controlling the film cation concentration is an effective way to tune the dielectric and insu- lating properties of SrTiO3/Si at the same time.