Alexander Gladkikh

Effect of microstructure on electromigration kinetics in Cu lines

Strong correlation of the modes of electromigration damage and microstructure is reported for Cu films. It is found that changes in the microstructure lead to qualitative variation in electromigration damage kinetics - from the traditional open circuit due to void growth across the line, to damage growing along the line, and not leading to failure. Some of our findings are consistent with the theoretical model based on interplay between surface and grain boundary diffusion. The activation energy eV of electromigration mass transport was measured using a modified electrical resistance method.

Critical oxygen content in porous anodes of solid tantalum capacitors

X-ray diffraction analysis of sintered porous anodes of solid tantalum capacitors and the current-voltage (I–V) characteristics of Ta2O5 amorphous layers formed on the anode surface have been performed. A strong correlation between a sharp increase of direct current in the I–V characteristics at some critical oxygen content and the creation of a saturated solid-phase solution of oxygen in tantalum was found. The appearance of a crystalline oxide Ta2O5 phase was detected in porous anodes at oxygen contents above the critical oxygen level. The decrease of effective radius below 1 μm of Ta powder particles used in sintering leads to the size effect: the oxygen content in the porous anode after sintering exceeds the solubility limit.

Preparation of Se-doped polyaniline emeraldine base films

Abstract Our letter focuses on the preparation of polyaniline emeraldine base films doped with selenium. PANI EB and Se were dissolved in dimethylsulfoxide. Thin films of selenium-doped PANI EB were obtained by spin-coating of Si and ZnSe substrates with a PANI EB+Se solution in DMSO. We studied the distribution of the selenium in the PANI EB films using time-of-flight secondary ion mass spectrometry (TOF-SIMS). The IR spectra of these thin films were obtained with an FT-IR spectrometer.

Metallic transport properties of amorphous nickel-silicon films

Transport properties including conductivity and magnetoconductance have been measured for amorphous nickel-silicon films. This study focuses on metallic amorphous a-Nix Si1 x films, located just above the metal-insulator transition (MIT). Using various techniques, the MIT was identified. Electron-electron interactions dominated the conductivity, where . 0/CCT 0:55 . Strong spin-orbit scattering was important in the weak-localization contribution to the magnetoconductance data for the metallic films. The inelastic scattering time was extracted from the magnetoconductance data. The low-temperature magnetoconductance data versus Ni content x exhibited a negative maximum just above the critical concentration xc, suggesting another technique for identifying the MIT.

Effect of thermal oxide on the crystallization of the anodic Ta 2 O 5 film

SEM and TEM investigations of the crystallization process have been performed on amorphous Ta2O5 films grown by electrochemical oxidation of Ta foils. It was found that kinetics of crystallization and final structure of the anodic Ta2O5 film depend strongly on the thickness of the thermal oxide layer on the surface of the original Ta substrate. Two different modes of crystallization were detected for the substrate with native surface oxide and with the thermal oxide grown at elevated temperatures. Aborting of the crystallization was shown to be possible using short heating of the Ta2O5/Ta san dwiches which cuts crystalline inclusions grown into the amorphous matrix of the anodic Ta2O5 film from the Ta surface.

Conduction processes in crystalline films

The electrical conductivity and magnetoconductance (MC) have been measured in crystalline nickel-silicon films as a function of nickel content, x. An abrupt decrease in the conductivity is observed at the metal-insulator transition where Ni. The discontinuity is explained in terms of a percolation model. Above 4 K, the magnetoconductance (MC) is negative and arises from an electron-electron interaction contribution and a weak-localization contribution involving strong spin-orbit scattering. Below 4 K, the magnetoconductance rapidly becomes positive. These low-temperature MC data can be explained using a model of electrons scattering from superparamagnetic particles, first introduced by Gittleman et al.

Polyethylene films doped with EU(III) complex: their optical properties and technological applications.

Light-converting polyethylene film containing Eu(III) complex with phenanthroline was manufactured under an extrusion process. The film was characterized by means of time-of-flight secondary-ion-mass spectrometry (TOF-SIMS), ultraviolet-visible-infrared (UV-Vis-IR) spectroscopy, study of excitation and luminescence spectra, quantum yield and lifetime of luminescence. TOF-SIMS surface mapping showed the uniform distribution of Eu(III) over the film. Typical Eu(III)-phenanthroline complex excitation and fluorescence spectra were recorded, the quantum yield of fluorescence being 5±2%. Luminescence lifetime was measured as 0.4 ms. Visualization of strong subpicosecond UV laser beams through the use of developed film has been demonstrated.

Microstructural and surface effects on electromigration failure mechanism in Cu interconnects

It is shown that changes in the microstructure of Cu interconnects lead to qualitative variation in electromigration damage kinetics - from the formation of the open circuit to continuous damage not leading to failure. Surface diffusion acting simultaneously with grain boundary mass transport is shown to be critical for damage formation. Activation energy of electromigration was measured to be 0.95 eV.

Indirect tunneling in metal-insulator-metal junctions

I- V characteristics of realistic MIM junctions were calculated assuming a two step indirect tunneling as the major mechanism. Electronphonon broadening of the energy level of the intermediate defect states is taken into account. The theory is compared with our experimental investigations of Pd-MgO-Pd junctions and good quantitative agreement is achieved. The intermediate states are provided by the F-centers of the MgO vacancies. A consistency between the experimental data and the theory is obtained for the values of the physical parameters known from independent studies on MgO.