Ultralow equivalent oxide thickness obtained for thin amorphous LaAlO_3 layers grown on Si(001)

摘要

Electron beam evaporation in a molecular beam epitaxy reactor was used to deposit, at 400 ℃, amorphous LaAlO_3 high-κ oxide films on p-type Si(001). X-ray photoelectron spectroscopy and transmission electron microscopy showed that the interface with Si is free of SiO_2 or silicates. Electrical measurements performed on as-deposited samples reveal an equivalent oxide thickness as low as 5 A for a film having a physical thickness of 41 A, a leakage current of 5.6 × 10~(-2) A/cm~2 at |V_g-V_(FB)|=1 V, and no flatband voltage shift.