Incorporation of SiO2 for the band alignment control of Gd2O3/n-GaAs(001) structure

Abstract Band alignment of Gd 2 O 3 gate oxide films on n -GaAs(0 0 1) was controlled by the incorporation of SiO 2 . The photoelectron binding energy shifts in Gd 2 SiO 5 film could be interpreted with relative electronegativity of second nearest neighbor element. The surface and interface morphology of Gd 2 SiO 5 / n -GaAs structure was smooth due to the absence of crystalline phase. Energy band gaps were estimated as ∼5.8 and 6.6 eV for Gd 2 O 3 and Gd 2 SiO 5 , respectively, by combining photoemission with absorption spectra. A decrease of leakage current density and a saturated accumulation capacitance indicate an enhanced band offset and small roughness in Gd 2 SiO 5 / n -GaAs system.