B. Gorenstein

Hot-Probe method for evaluation of impurities concentration in semiconductors

Abstract Electrical, optical, and mechanical properties of thin films significantly differ from those of bulk materials. Therefore, characterization methods for evaluation of thin film properties became highly important. A novel approach to the well known “Hot-Probe” method is proposed and applied in our work. The conventional Hot Probe characterization method enables only the definition of a semiconductor type, P or N, by identifying the majority charged carriers. According to the new Hot Probe technique, one can measure and calculate the majority charged carriers concentration and its dynamic parameters. Feasibility proof of the upgraded Hot Probe method was done in Si and Ge bulk, and in thin film semiconductor samples.

Sputtered gold nano-structure for photovoltaic applications

Islet ultra-thin gold films are used extensively in various fields of science and technology in recent years. Their widespread use is based on the occurrence of plasmon-polaritons in these films upon irradiation with light. When exposed to light, small gold particles are polarized and electrons within them begin to oscillate together. To produce such nano-dimensional gold islands, we used various deposition techniques: triode sputtering in the low-pressure plane plasma discharge, magnetron sputtering, and thermal evaporation methods. In our experiments, island gold films were embedded into the p-n junction of a silicon photovoltaic structures using the sputtering method. The resulting samples of silicon solar cells with the non-continuous gold interlayer showed a substantial increase in efficiency.

Investigation of Metal-Polycrystalline Silicon Carbide Bonding While Metallization

Polycrystalline silicon carbide heaters or heated substrates are widely used within the semiconductor industry. The problem of making reliable contacts between such SiC and various metals is most relevant. The main goal of our investigation was an experimental study of molten metals (Fe, Cu, Cr) behavior on top of surfaces of polycrystalline silicon carbide SiC. The mechanism of melt-polycrystalline SiC interaction was found and reported. Non-wetting metal in a liquid phase penetrates into the micro and macro volumes in the polycrystalline SiC surface and holds there due to the residual stresses originated by the difference in the linear expansion coefficients. Metal layers obtained on the poly-crystalline SiC surfaces by the described method were durable and stable

Optimization in vacuum photothermal processing (VPP)

Recent development in RTP enables the expansion of synergetic influence of electron flux and non-coherent light, mainly from UV and VUV spectrum, on treated samples. This expansion is called vacuum photothermal processing (VPP). The treatment consists of a simultaneous irradiation of samples with electron flux and non-coherent light produced by a heated tungsten coil in vacuum. This paper presents studies of the influence of VPP on the interface between silicon substrates and metal coatings deposited on top of it was found that VPP provides for stabilizing the deposited coatings, improves homogeneity and curing the irreversible electrical breakdown in thin-film systems; it also improves the roughness of interfaces between semiconductor and metal coatings. These modifications and improvements are explained by the appearance of an intermediate layer which is made up while VPP and passivates the interface. This built-in layer, produced during VPP treatment, was discovered and is shown in this study