Initial growth of Ga2O3(Gd2O3) on GaAs: Key to the attainment of a low interfacial density of states

Abstract

Growth of the first few layers of an oxide mixture Ga 2 O 3 ͑Gd 2 O 3 ͒ on GaAs ͑100͒ substrate, electron-beam evaporated from a Ga 5 Go 3 O 12 source, was found to be a single crystal. Reflection high-energy electron diffraction and x-ray diffraction studies show that the thin oxide film is epitaxially grown on GaAs with the surface normal ͑110͒ and in-plane axis ͓001͔ parallel to ͑100͒ and ͓011͔ of GaAs, respectively, and has a structure isomorphic to Mn 2 O 3. Studies using high-resolution transmission electron microscopy on the oxide-GaAs interface indicate some atomic registry between the oxide and GaAs during the initial growth. The chemical composition of the oxide film was determined by x-ray photoelectron spectroscopy to be unequivocally pure Gd 2 O 3 .

Heteroepitaxy of La2O3 and La2–xYxO3 on GaAs (111)A by Atomic Layer Deposition: Achieving Low Interface Trap Density

“…Getting MOSFETs even of this quality also requires that there is no air-break between growth of the GaAs and the oxide, so that complex multichamber MBE systems are necessary. Several follow-up structural analyses of Gd 2 O 3 /GaAs(100) [11][12][13] revealed that perfect strained epitaxy only occurs in the first few layers.…”

MBE grown high κ dielectrics Ga2O3(Gd2O3) on GaN

“…The results are similar to the initial growth of Ga 2 O 3 (Gd 2 O 3 ) on GaAs. [7] However, the structure of Gd 2 O 3 on GaN is hcp, [8] Fig. 2 shows the J-E curves of a MOS diode with an oxide film 25 nm thick in the asdeposited condition as well as after forming gas annealing at 400 and 600 1C.…”

Depletion-mode In0.2Ga0.8As/GaAs MOSFET with molecular beam epitaxy grown Al2O3/Ga2O3(Gd2O3) as gate dielectrics

“…The relatively higher D it 's in the ALDAl 2 O 3 on GaAs or InGaAs is probably caused by the existence of In 2 O 3 and Ga 2 O 3 at the interface, while there are no such native oxides in those cases using MBE-GGO [10,16]. GGO, containing rare earth Gd, tends to absorb moisture during air exposure, thus degrading the electrical properties [17]. In-situ deposited Al 2 O 3 was found to be very effective in protecting GGO from absorbing moisture to give an excellent thermodynamic stability [18,19].…”