A microwave magnetic field crossed with a static field was found to exert a resonance effect on the dislocation mobility in single crystals of p-type silicon. The frequency of alternating field and the magnitude of static magnetic field corresponding to the maximal crystal hardening satisfy conditions for EPR of structural defects. This is evidence that the primary elementary processes observed previously in magnetoplasticity effects (influence of a static magnetic field on plasticity) are spin-dependent in silicon crystals. The dislocation path detected EPR spectrum was found to be anisotropic.

Residual charges of individual microparticles forming dense clouds were measured in a RF discharge afterglow. Experiments were performed under microgravity conditions on board the International Space Station, which ensured particle levitation inside the gas volume after the plasma switch-off. The distribution of residual charges as well as the spatial distribution of charged particles across the cloud were analyzed by applying a low-frequency voltage to the electrodes and measuring amplitudes of the resulting particle oscillations. Upon “free decharging” conditions, the charge distribution had a sharp peak at zero and was rather symmetric (with charges concentrated between −10e and +10e), yet positively and negatively charged particles were homogeneously distributed over the cloud. However, when decharging evolved in the presence of an external DC field (applied shortly before the plasma switch-off) practically all residual charges were positive. In this case, the overall charge distribution had a sharp peak at about +15e and was highly asymmetric, while the spatial distribution exhibited a significant charge gradient along the direction of the applied DC field.

The work is devoted to the study of contact melting in the Al-Si system, which is an aluminum film deposited on a silicon single-crystal substrate. The impulse action of high-density currents (j> 8.1010 A / m2) passing through an aluminum film is analyzed. It was found that under the considered electric heat loads in the system, the degradation processes associated with the appearance of a molten aluminum zone and subsequent contact melting in the metal-semiconductor system develop. From the analysis of contact melting processes, a technique for estimating the coefficients of multiphase diffusion in the system under consideration is a thin aluminum film-single-crystal silicon substrate.

Contents IJPAM: Volume 111, No. 3 (2016)

Purpose: The purpose of this study is to investigate the mechanisms of degradation of aluminum metallization under conditions of thermal shock caused by rectangular current pulses (amplitude j < 8 × 10¹⁰ A/m², duration t < 800 μs). Design/methodology/approach: The results were obtained using oscillography and optical microscopy and through the construction of an empirical model of the thermal degradation of metallization systems. Findings: Initially, for the authors’ studies, they deduced an equation that associated the depth of melting with the parameters of a current pulse. Research limitations/implications: The authors were able to observe effects only in systems with appropriate adhesion of the thin metal films. For the systems with bad adhesion, the main mechanisms of degradation were associated with the melting of the metal, the formation of melted drops (up to 20 mcm in size) and the movement of these drops along the electrical field due to the electrocapillary effect. Practical/implications: The mechanisms the authors studied could only occur in high-power semiconductor devices. Originality/value: The principal mechanism of melting of a metallization track is linked to the heat dissipation at the interface of solid and liquid phases under conditions of thermal shock. The authors estimated the mechanical stresses in subsurface layers of silicon in the proximity of a non-stationary thermal source. The authors’ results show that the mechanical stresses that are strong enough to form dislocations emerge with current flow with power measuring approximately 0.7 Pkr.