In this paper we attempt to quantitatively describe the process of diffusion of Nickel atoms to the copper substrate, taking into account the accelerated diffusion along the grain boundaries. A model experiment allows us to get guidance on the selection of the optimum thickness of the Nickel coating to ensure stable operation of wire with desired characteristics
Keywords: Nickel coating, the optimum thickness, copper wire, enhanced diffusion, diffusion coefficient, diffusion distribution of atoms, the grain boundary, modeling, task Fisher
A method of prognosis of gas sensitivity's coefficient of conductometric gas sensors with sensitive layer which is based on a semiconductor with deep energy levels in the fobidden zone was developed. As a result it was found out that deep energy levels can cause a significant increasing of gas sensitivity's coefficient as well as influence on the chemosorptive properties of sensitive layer.
Keywords: Сonductometric gas sensor, gas sensitivity, sensitive layer, semiconductor, deep-lying levels.
In the introduction the relevance of the study of diffusion along grain boundaries in metals. The aim of the work was to develop a method for determining the diffusion coefficient of impurity atoms at the grain boundaries in metals based on the numerical solution of the model by Fisher. The methodology laid plotting the ratio of the depth of bulk diffusion and grain boundary diffusion on the ratio of the diffusion coefficients of impurity atoms in them. In the construction of numerical solutions available to simplify the modeling of the physical nature of the process of diffusion along grain boundaries. The technique may be used in experiments with widely varying parameters diffusion annealing. Examples of the application procedure. The estimation of the coefficient of grain-boundary diffusion of copper in polycrystalline nickel. Also calculated the ratio of maximal depth of diffusion of silver in the grain and the grain boundary in the SMC copper.
Keywords: diversification of management, production diversification, financial and economic purposes of a diversification, technological purposes of ensuring flexibility of production
The simulation of the process of the electrically active impurities relocation in the electric field of Schottky diode space charge region has been made. The analysis of the simulation results shows the possibility of controlled alloying impurities relocation on the depth about tens of nanometers caused by electrically active atoms diffusion in the electric field of Schottky diode space charge region.
Keywords: diffusion, space charge region, Schottky diode
The peculiarities of modification of silicon’s surface structure by the electric disintegration were researched. It was established that the electric disintegration of sensitive layer’s surface increases its effective area and the density of surface state. It also forms the deep energy levels in the forbidden zone of the semiconductor which are conditioned by atoms of the electrode’s material and by dislocation. In total it makes possible to modify the sensitivity and selectivity of gas sensors.
Keywords: modification of surface, sensitive layer, gas sensor, electric disintegration
The mathematical model of the potential distribution in the semiconductor surficial region in the presence of deep-lying levels in its forbidden zone which specified by multiple-charge impurity centers has been developed. The simulation results can be used for the width of the space charge region estimation, for the prognostication of the most probable mechanism of the charge carriers transfer in metal-semiconductor structure with multiple-charge deep-lying levels and also for the prognostication of the barrier capacitance value. It can be used in the development of solid-state electronic devices with improved values of some parameters.
Keywords: Poisson’s equation, multiple-charge impurity center, potential distribution, deep-lying levels