AS “KEPP EU” in cooperation with the project “Mašīnbūves Kompetences centrs izveide” SIA “MAŠĪNBŪVES KOMPETENCES CENTRS”, within the framework of the project ID Nr. 1.2.1.1/16/A/003, December 31, 2018 together with SIA “PAIC” completed the study Nr. 2.3 “Elektronu staru sildītāju plazmas lādiņa formas modelēšana un tā formas optimizācija kristālu audzēšanas procesa vadības uzlabošanai” (Simulation of the plasma charge shape in an electron-beam heater and its optimization to improve control during crystal growth).
A mathematical model of the processes occurring in an electron-beam heater has been developed;
A plasma discharge visualization camera was manufactured, and the process was photographed. The result showed that the mathematical model describes the process satisfactorily. Work must be continued with the use of reinforced light filters and increased image clarity;
Based on the constructed model, the parameters of the electron beam near the silicon surface are determined. The total area of electron irradiation is determined. Based on this, a decrease in the radius of curvature of the anode surface and an increase in the aperture of the cathode are recommended. In experiments, attempts were made to prevent the entry of electrons into technological equipment, and it was found that this process is a source of silicon contamination with iron and makes a significant contribution to silicon contamination with copper.
Experiments were carried out to remove impurities (aluminum and copper), which are formed in the volume of gas plasma and contaminate the silicon alloy. A gas-dynamic window was manufactured and tested at currents up to 2A; a decrease in the gas flow to the melt up to 20 times was shown.
Based on the research results, two articles were published:
Development of silicon growth techniques with surface heating
Modeling electron beam parameters and plasma interface position in an anode plasma electron gun with with hydrogen atmosphere
