Tsybulsky L. Development of scientific foundation of modeling and designing improved induction evaporators

Developed physical-topological mathematical model of the induction evaporator which allows to set a numerical calculation of the magnetic field distribution, to set the distribution of sources of heat, temperature, heat flows in the loaded crucible as well as integral characteristics of the induction evaporators. It is proved that the power consumed by the loaded crucible at a predetermined average evaporation temperature does not depend on the frequency of the inductor current in the range 100-500 kHz but determined by the voltage on the inductor; in the evaporator with an inductor whose height is greater or equal to the diameter the temperature of the evaporation surface can be considered the same with the margin of error not more than 1%. The technique for three-dimensional modeling of mass-transport onto substrate surface with different substrate movement and orientation in space is developed. The mass-transfer is described by integral equations for the functions of flows from the melt surface and the crucible cylindrical walls. It is proposed a method and a crucible with heat-resistive and heat-sink shielding elements that will prevent overflow of the melt through the crucible edge while evaporating metal, which migrates up along the surface of the crucible walls. It is proposed to introduce a magnetic field concentrator between the inductor and the crucible, the use of which reduces the likelihood of electrical discharges in the crucible area and provides a non-ionized vapor flow. The influence of evaporator design features on radiation resistance of MOS-structure during their metal deposition processing is determined. The use of the crucible with the heat-resistive and heat-sink shielding elements and the magnetic field concentrator enhances the radiation resistance of MOS-structure relatively the structures processed with a non-shielded evaporator. The conditions for electrical discharging in the induction evaporators. The hollow-cathode discharge in metal vapor within the crucible of induction evaporator is revealed and investigated. The arising of non-self-maintaining arc-type discharge in the vapor flow, when a thermo-emission-active insert is set into the upper part of the crucible, the insert is heated above a certain temperature, and a positive potential is applied to the top turn of the inductor, is identified and examined.