Atomic-layer-deposited high dielectric HfO 2 films on air-exposed In 0.53 Ga 0.47 As/ InP ͑100͒, using Hf͑NCH 3 C 2 H 5 ͒ 4 and H 2 O as the precursors, were found to have an atomically sharp interface free of arsenic oxides, an important aspect for Fermi level unpinning. A careful and thorough probing, using high-resolution angular-resolved x-ray photoelectron spectroscopy ͑XPS͒ with synchrotron radiation, however, observed the existence of Ga 2 O 3 , In 2 O 3 , and In͑OH͒ 3 at the interface. The current transport of the metal-oxide-semiconductor capacitor for an oxide 7.8 nm thick follows the Fowler-Nordheim tunneling mechanism and shows a low leakage current density of ϳ10 −8 A / cm 2 at V FB + 1 V. Well behaved frequency-varying capacitance-voltage curves were measured and an interfacial density of states of 2 ϫ 10 12 cm −2 eV −1 was derived. A conduction-band offset of 1.8Ϯ 0.1 eV and a valence-band offset of 2.9Ϯ 0.1 eV have been determined using the current transport data and XPS, respectively.

Electron mobility, Hall scattering factor, and sheet conductivity in AlGaN/AlN/GaN heterostructures J. Appl. Phys. 110, 113713 (2011) Reduction of the potential energy barrier and resistance at wafer-bonded n-GaAs/n-GaAs interfaces by sulfur passivation J. Appl. Phys. 110, 104903 (2011) Diameter reduction of nanowire tunnel heterojunctions using in situ annealing Appl. Phys. Lett. 99, 203101 (2011) Substrate nitridation induced modulations in transport properties of wurtzite GaN/p-Si (100) heterojunctions grown by molecular beam epitaxy J. Appl. Phys. 110, 093718 (2011) Characteristics of a-GaN films and a-AlGaN/GaN heterojunctions prepared on r-sapphire by two-stage growth process

A comparison of the water vapor oxidation characteristics of AlAs, Al 0.98 Ga 0.02 As, and an Al x Ga 1Ϫx As digital alloy was performed. The Al x Ga 1Ϫx As digital alloy consists of periods of 49 monolayers of AlAs and 1 monolayer of GaAs and has an equivalent composition of xϭ0.98. Oxidation rates and the structural integrity of the three layers were compared. When oxidized in water vapor, the Al x Ga 1Ϫx As digital alloy and the AlAs have similar oxidation rates, both of which are twice as fast as the Al 0.98 Ga 0.02 As layer. Post-oxidation annealing of these samples at 450°C showed severe delamination at the oxide/GaAs interface in the AlAs sample while the Al x Ga 1Ϫx As digital alloy sample was not damaged.

In this study, the interface adhesion and mechanical strength of wafer bonded GaAs/GaAs and GaAs/InP semiconductors, each of (100) face, were characterized by combining the measurements of interface fracture energy γo and lap shear strength Es. The relations between the interface adhesion and annealing processes for four different types of bonding configurations, i.e., antiphase bonding, in-phase bonding, and twist bonding with 5° and 30° misalignments, were systematically studied. The surface free energy γα-GaAs/oxide (0.11–0.28 J/m2) of amorphous α-GaAs/oxide mixture was estimated based upon the reported surface free energy γc-GaAs (0.63 J/m2) of crystalline [100] GaAs and measured overall interface fracture energy γtotal (0.525 J/m2) of GaAs/GaAs bonded wafers. The micromorphologies of the bonded and debonded wafer interfaces were characterized by atomic force microscopy (AFM) and transmission electron microcopy (TEM). The interface microfailure mechanism of directly bonded GaAs wafers was proposed based on AFM and TEM microstructural analysis.

In this brief, we propose a variable structure based nonlinear missile guidance/autopilot system with highly maneuverable actuators, mainly consisting of thrust vector control and divert control system, for the task of intercepting of a theater ballistic missile. The aim of the present work is to achieve bounded target interception under the mentioned 5 degree-of-freedom (DOF) control such that the distance between the missile and the target will enter the range of triggering the missile's explosion. First, a 3-DOF sliding-mode guidance law of the missile considering external disturbances and zero-effort-miss (ZEM) is designed to minimize the distance between the center of the missile and that of the target. Next, a quaternion-based sliding-mode attitude controller is developed to track the attitude command while coping with variation of missile's inertia and uncertain aerodynamic force/wind gusts. The stability of the overall system and ZEM-phase convergence are analyzed thoroughly via Lyapunov stability theory. Extensive simulation results are obtained to validate the effectiveness of the proposed integrated guidance/autopilot system by use of the 5-DOF inputs.