The resistivity of thin Cu films depends on film thickness as the dimensions approach the electron mean-free-path for Cu of 39 nm. The key size-dependent contributions are from electron–surface scattering, grain boundary scattering, and surface roughness-induced scattering. Measurements with pseudoepitaxial Cu films deposited on Si have been undertaken to reduce effects of grain boundaries and surface roughness and suggest an electron-scattering parameter of p=0.12. Overlayers of metal films on the Cu generally increase the resistivity for Ta and Pt overlayers, and may reduce the resistivity for Au and Al. The resistivity increase may also be reversed if the overlayer oxidizes.

Blue light emitting diode internal and injection efficiency AIP Advances 2, 032117 (2012) Enhancement of hole injection and electroluminescence characteristics by a rubbing-induced lying orientation of alpha-sexithiophene J. Appl. Phys. 112, 024503 (2012) Study of field driven electroluminescence in colloidal quantum dot solids J. Appl. Phys. 111, 113701 (2012) Indium incorporation and emission properties of nonpolar and semipolar InGaN quantum wellsElectroluminescence from metal-insulator-semiconductor structures with silicon dioxide (SiO z ) layers containing varying amounts of excess silicon (Si) in the form of tiny Si precipitates have been studied in detail. Bulk insulator emission from the Si islands is shown to dominate over emission from either the Si0 2 matrix material or the metallic gate material by studies of oxide or metal gate material, voltage polarity, and insulator thickness dependencies. Several distinct spectral peaks are observed in the energy range from 1.5 to 5 eV which cannot be attributed to optical interference effects. The higher-energy peaks show a strong dependence on electric field relative to that at the lowest energy (1.7-2 eV). The entire spectral amplitude shows a strong dependence on high-tempera.ture annealing and excess Si content, decreasing drastically with increasing Si or decreasing annealing temperature. These results are shown to be consistent with light emission during electronic transitions between discrete energy levels associated with Si islands and/or their interface with the Si0 2 host matrix material. Quantum size effects, similar to those observed in semiconductor superlattices, are proposed as one possible explanation.

We report the first observation of long-range order in a semiconductor III-V ternary alloy. Al x Gai_ x As thin crystals grown by metal-organic chemical vapor deposition or molecular-beam epitaxy have Ga atoms preferentially occupying the 0,0,0 and y,y,0 sites and Al atoms the y>0>T and 0,y,y sites in each unit cell. Our results indicate that this ordered structure is the equilibrium state of Al^Gai-xAs.

The knowledge on the influence of surface roughness and the electron-phonon (el-ph) interaction on electrical transport properties of nanoscale metal films is important from both fundamental and technological points of view. Here we report a study of the temperature dependent electron transport properties of nanoscale copper films by measuring temperature dependent electrical resistivity with thickness ranging from 4 to 500 nm. We show that the residual resistivity, which is temperature independent, can be described quantitatively using both measured vertical surface root-mean-square roughness and lateral correlation length in the nanoscale, with no adjustable parameter, by a recent quasi-classical model developed by Chatterjee and Meyerovich (2010 Phys. Rev. B 81 245409-10). We also demonstrate that the temperature dependent component of the resistivity can be described using the Bloch-Grüneisen equation with a thickness dependent el-ph coupling constant and a thickness dependent Debye temperature. We show that the increase of the el-ph coupling constant with the decrease of film thickness gives rise to an enhancement of the temperature dependent component of the resistivity.

The relaxation of patterned, compressively strained, epitaxial Si0.7Ge0.3 films transferred to borophosphorosilicate (BPSG) glass by a wafer-bonding and etch-back technique was studied as an approach for fabricating defect-free Si1−xGex relaxed films. Both the desired in-plane expansion and undesired buckling of the films concurrently contribute to the relaxation. Their relative role in the relaxation process was examined experimentally and by modeling. Using x-ray diffraction, Raman scattering and atomic force microscopy, the dynamics of in-plane expansion and buckling of Si0.7Ge0.3 islands for island sizes ranging from 10 μm×10 μm to 200 μm×200 μm for anneal temperatures between 750 and 800 °C was investigated. Lateral relaxation is favored in small and thick islands, and buckling is initially dominant in large and thin islands. Raising the temperature to lower viscosity of the oxide enhances the rate of both processes equally. For very long annealing times, however, the buckling disappeared, allowing larger, flat, and relaxed islands to be achieved. Cross-sectional transmission electron microscopy observation on a relaxed Si0.70Ge0.30 island revealed no dislocations, confirming that SiGe relaxation on BPSG is a good approach to achieve high quality relaxed SiGe.