Electromigration in integrated circuits

We review the mechanism of integrated circuit failure known as “electromigration.” Electromigration is a physical wearout process that operates primarily in the on-chip interconnections of an integrated circuit. It is caused by the currents that run through those interconnections. The first part of the review introduces the founding principles of electromigration and the research history upon which those principles are based. The second part introduces and reviews the increasingly relevant issue of pulsed current electromigration, and the final part contains a relatively detailed review of a recent study of pulsed current electromigration.     

Effects of the addition of mango residue on solution combustion synthesis of iron oxides

Journal of Thermal Analysis and Calorimetry - The effects of the addition of mango residue on the combustion of iron nitrate–urea mixtures are presented herein. The process was performed...     

L2(R) Solutions of Dilation Equations and Fourier-Like Transforms

We state a novel construction of theFourier transform on L²(R) based on translation and dilation properties which makes use of the multiresolution analysis structure commonly used in the design of wavelets. We examine the conditions imposed by variants of these translation and dilation properties. This allows other characterizations of the Fourier transform to be given, and operators which have similar properties are classified. This is achieved by examining the solution space of various dilation equations, in particular we show that the L²(R) solutions of f (x) = f (2x) + f (2x - 1) are in direct correspondence with L²(-[1, 2)).     

空气中激光烧蚀Cu产生等离子体发射光谱的研究

利用Q-开关Nd:YAG激光器产生的1.06 μm、10 ns的脉冲激光聚焦在空气中的Cu靶上,观测了激光诱导的Cu等离子体发射光谱.采用不同的激光能量,分析了波长范围为440 nm到540 nm的空间分辨发射光谱.在局部热力学平衡(LTE)条件近似下,根据谱线的相对强度,得到了等离子体电子温度约在104 K以上,给出了靶面附近电子温度的空间演化规律,并探讨了N(Ⅱ)500.52 nm谱线的谱线强度和半高全宽随激光能量的变化规律.     

Experimental characterization of nonlinear harmonic radiation from a visible self-amplified spontaneous emission free-electron laser at saturation

Nonlinear harmonic radiation was observed using the VISA self-amplified, spontaneous emission (SASE) free-electron laser (FEL) at saturation. The gain lengths, spectra, and energies of the three lowest SASE FEL modes were experimentally characterized. The measured nonlinear harmonic gain lengths and center spectral wavelengths decrease with harmonic number, n, which is consistent with nonlinear harmonic theory. Both the second and third nonlinear harmonics energies are about 1% of the fundamental energy. These experimental results demonstrate for the first time the feasibility of using nonlinear harmonic SASE FEL radiation to produce coherent, femtosecond x rays.     

Surface-roughness wakefield measurements at brookhaven accelerator test facility

An experiment has been carried out at the Brookhaven Accelerator Test Facility to investigate the effect of a surface-roughness wakefield in narrow beam tubes with artificially created bumps. The measurements show that the synchronous modes decay significantly due to the randomization of the roughness pattern. It is pointed out that this decay mechanism has not been investigated in the previous experiment at DESY and the investigators' conclusion does not apply for surface-roughness wakefields in real surfaces.     

Stress-induced diffusion of macromolecules

A framework for analysis of stress-induced diffusion is presented. Diffusion of macromolecules is considered to be driven by gradients of entropic potential arising from distortion of the molecular conformation by deformation, as well as by gradients of concentration of individual molecular weight species. Resulting concentration profiles in circular capillary flow have been calculated for a system containing a single macromolecular species. Significant variations in concentration with capillary radius are predicted at full development. Estimates of the dynamics of development of these profiles indicate that the length to diameter ratios needed to see a measurable effect are proportional to the Peclet number, which may be quite large for macromolecular fluids depending on the geometry and flow velocity of the system. This effect may have implications in the rheology, chromatography, and technological uses of macromolecular fluids.     

Separating forces in blade coating of viscous and viscoelastic liquids

Coating of viscous and viscoelastic liquids is examined both theoretically and experimentally. A single simple geometry, a blade over a rotating roll, is considered. A perturbation solution to the Navier-Stokes equations yields a lubrication theory with first order corrections for curvature and inertia. A numerical solutions by the Finite Element Method (FEM) is compared to the analytical solutions. For Newtonian fluids, agreement between these mathematical models, and data on blade loading, is quite good.The effect of a non-Newtonian viscosity is explored by adopting a purely viscous power law model. The zeroth-order (lubrication) equations are solved by the method of Steidler and Horowitz, and predictions for coating thickness and blade loading agree quite well with those obtained from a FEM solution of the full equations of motion for a power law fluid. Data on blade loading, obtained using a strongly elastic polymer solution, are compared to these mathematical models, and discrepancies are noted.     

Annealing effect on semi-crystalline materials in creep behavior

Three glass reinforced polymers of Nylon 66, PET and HT-Nylon with glass transitions of 58, 72, and 132°C are selected for checking the necessity of high temperature annealing and degree of its impact on creep strains. The improvement after annealing depends on the polymer type of whether it is fast or slow crystallizing at molding process and whether it has hydrogen bonded sheets. The physical property changes observed of these materials before and after annealing support the explanation of crystal reorganization through crystallization, free volume reduction through densification and crystal perfection through better chain packing. The prediction of long-term creep strains up to 10 years using time-temperature superposition technique has been the practice for last 13 years in our laboratory. The accuracy of the prediction are shown in confidence level of about 90%.This revised version was published online in November 2005 with corrections to the Cover Date.     

Steric and stereoelectronic effects in the synthesis and photoisomerization of a dinitrone of 2,2,4,4-tetramethylcyclobutanedione

Peroxyacid oxidation of diimine (1) yielded only the $\text{trans}$ isomer of dinitrone (2) which upon photoisomerization gave dioxaziridines (3a) and (3b) and amide (4) as the only isolable isomers; an X-ray crystallographic investigation of (1) shows a considerable geometry distortion.