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We report the structural properties and spatial ordering of multilayer ZnMgTe quantum dots (QDs) embedded in ZnSe, where sub-monolayer quantities of Mg were introduced periodically during growth in order to reduce the valence band offset of ZnTe QDs. The periodicity, period dispersion, individual layer thickness, and the composition of the multilayer structures were determined by comparing the experimental high resolution x-ray diffraction (HRXRD) spectra to simulated ones for the allowed (004) and quasi-forbidden (002) reflections in combination with transmission electron microscopy (TEM) results. Secondary ion mass spectroscopy (SIMS) profiles confirmed the incorporation of Mg inside the QD layers, and the HRXRD analysis revealed that there is approximately 32% Mg in the ZnMgTe QDs. The presence of Mg contributes to higher scattering intensity of the HRXRD, leading to the observation of higher order superlattice peaks in both the (004) and (002) reflections. The distribution of scattered intensity in the reciprocal space map (RSM) shows that the diffuse scattered intensity is elongated along the qx axis, indicating a vertical correlation of the dots, which is found to be less defined for the sample with larger periodicity. The diffuse scattered intensity is also found to be weakly correlated along the qz direction indicating a weak lateral correlation of the dots. [ABSTRACT FROM AUTHOR]

Single-phase Ba(Cd1/3Ta2/3)O3 powder was produced using conventional solid state reaction methods. Ba(Cd1/3Ta2/3)O3 ceramics with 2 wt % ZnO as sintering additive sintered at 1550 °C exhibited a dielectric constant of ∼32 and loss tangent of 5×10-5 at 2 GHz. X-ray diffraction and thermogravimetric measurements were used to characterize the structural and thermodynamic properties of the material. Ab initio electronic structure calculations were used to give insight into the unusual properties of Ba(Cd1/3Ta2/3)O3, as well as a similar and more widely used material Ba(Zn1/3Ta2/3)O3. While both compounds have a hexagonal Bravais lattice, the P321 space group of Ba(Cd1/3Ta2/3)O3 is reduced from P3_m1 of Ba(Zn1/3Ta2/3)O3 as a result of a distortion of oxygen away from the symmetric position between the Ta and Cd ions. Both of the compounds have a conduction band minimum and valence band maximum composed of mostly weakly itinerant Ta 5d and Zn 3d/Cd 4d levels, respectively. The covalent nature of the directional d-electron bonding in these high-Z oxides plays an important role in producing a more rigid lattice with higher melting points and enhanced phonon energies, and is suggested to play an important role in producing materials with a high dielectric constant and low microwave loss. [ABSTRACT FROM AUTHOR]

Presents a study which measured and plotted the dependence of secondary-ion-mass spectrometry (SIMS) relative sensitivity factor (RSF) on electron affinity and ionization potential using oxygen-ion atom bombardment and positive SIMS, and cesium-ion bombardment and negative SIMS. Reproducibility in RSF; Regions in the dependence of logRSF on ionization potential; Values of slope of logRSF versus ionization potential for the matrices studied.

Presents study which measured simultaneous depth profiles for hydrogen and lithium in proton-exchanged lithium niobate crystals. Experimental details; Results and discussion; Conclusion.

Presents a study that introduced atomic hydrogen by two methods into gallium arsenide (GaAs) layers epitaxially grown on silicon substrates. Correlation of the amount of hydrogen incorporated during plasma exposures with the amount of initial disorder in the GaAs layer; Use of current-voltage measurements in titanium-platinum-gold Schottky diode structures; Effects of the defects in the GaAs layer.

Describes a model for analyzing hydrogen and lithium diffusion in annealed proton exchange (PE) LiNbO[sub3] crystals. Details of the experimental procedures; Diffusion analysis for the depth profiles in an annealed X-cut PE LiNbO[sub3] samples; Discussion on similarities and differences found in the analysis of Z- and X-cut material.

Presents a study which investigated focused ion beam (FIB) gallium (Ga) ion implantation through titanium metal (ITM) and TiSi[sub2] (ITS) layers followed by rapid thermal annealing, in self-aligned silicide technology. Overview of research on salicide technology; Details of an experiment on FIB Ga ion implantation; Description of the as-implanted Ga obtained from the ITS simulation; Current-voltage characteristics for ITM and ITS diodes.

Presents information on a study which measured normalized positive ion yields of more than twenty elements implanted into SiO[sub2] and compared them with positive ion yields of the same elements sputtered from silicon by oxygen and argon ion bombardment. Calculation of relative sensitivity factors; Logarithm of the measured secondary ion mass spectrometry relative sensitivity factor; Implications of the rotation of the primary trend.

Cu-related green luminescence (GL) band in n-type ZnO layers grown by molecular beam epitaxy on sapphire and a bulk ZnO sample grown by hydrothermal method have been studied with above-bandgap excitation. Annealing of the samples in air at temperatures above 600 °C resulted in an increase in the concentration of CuZn acceptors, followed by a dramatic enhancement of the Cu-related GL band peaking at 2.45 eV, and a characteristic fine structure. The GL band quenched at temperatures between 250 and 500 K due to escape of holes from the excited state of the CuZn acceptor to the valence band. Energy position of this state in the bandgap of ZnO and its capture cross section for holes were estimated as 0.38 eV and 2×10-13 cm2, respectively. [ABSTRACT FROM AUTHOR]

The authors investigate growth behavior, morphology, and doping of Ge grown selectively on silicon in submicron SiO2 trenches, in comparison with growth on blanket Si. Based on the surface morphology of Ge in trenches, it appears that lateral transport of Ge-containing species over the SiO2 surface extends on the order of ∼100 μm from the trench. For growth at 600 °C, preferential nucleation at trench edges leads to significant surface roughness. Contrary to behavior on blanket Si, reduction in growth temperature to 400 °C leads to increased Ge roughness in trenches. Finally, with very low temperature of 350 °C a very smooth surface in the trenches is achieved. Growth on blanket Si at this temperature is impractically slow, but is appreciable in the trenches; a discrepancy arising from the dominant supply of Ge-containing species migrating from the oxide. For boron and phosphorus-doped Ge inside the trenches, boron and phosphorus doping levels inside the trenches were about a half of those on blanket. [ABSTRACT FROM AUTHOR]

Copper oxide resistive memory layers have been synthesized by ion implantation. Devices fabricated from off-stoichiometric Cu2O exhibited unipolar switching in forward/reverse bias without a forming voltage. The on-state conduction of these devices is likely dominated by a metallic filament, which ruptures via Joule heating to transition the device to the high resistance off-state. Technology scaling was achieved by oxygen implanting copper filled vias. The resulting via-based memory devices exhibited unipolar resistive switching down to 48 nm in diameter. [ABSTRACT FROM AUTHOR]

Demonstrates the growth of p-type carbon-doped lattice matched GaInAs on InP(100) based on chemical beam epitaxy using carbon tetrachloride as C-dopant gas. Use of trimethylindium, triethylgallium and cracked arsine; Fabrication of C-doped base InP/InGaAs bipolar transistors; Presence of elemental and organometallic group-III p-type layers.

Effects of extended defect evolution on the anomalous diffusion of ion-implanted boron during rapid thermal annealing (RTA) have been studied using transmission electron microscopy and secondary-ion mass spectroscopy. It has been found that for low-dose boron implants (<1×1014 cm-2), no extended defects can be observed after RTA at 1000 °C, and the anomalous diffusion saturates within less than 10 s. However, extended defects are developed for high-dose boron implants (>5×1014 cm-2), and the anomalous diffusion persists for a much longer time and is dose dependent. Extended defect evolution has been characterized and correlated with the observed anomalous boron diffusion behaviors. [ABSTRACT FROM AUTHOR]