Create the energy-efficient technology to produce polycrystalline silicon

Since the beginning of Project No. 2/EEZLV02/14/AK/010/005 supervised by State Regional Development agency(VRAA) «Create the energy-efficient technology to produce polycrystalline silicon» a number of works have been conducted, which shall enable obtaining of silicon rods with parameters in accordance with requirements of power microelectronics in the process of ingot pulling with electron beam heating

– Mutual position of electron beam heaters and means of evacuation on the industrial development furnace was changed to eleminate dissymmetry during evacuation of vacuum volumes of heaters and main vacuum volume containing pulled rod

– To access the influence of substances, originating from heaters’vacuum volumes, on the main vacuum volume containing pulled rod, further works were carried out at laboratory and industrial development furnaces:
a) on beam generation with helium instead of hydrogen
b) on using heaters with smaller hydrogen consumption
c) new approaches were devised for evacuation efficiency enhancement in order to minimize mutual influence of vacuum volumes

– First samples were prepared from single silicon crystals grown from rods obtained in the project. Samples were transferred to the Institute of Solid State Physics, University of Latvia, for assessment of their purity by low temperature FTIR analysis. Also contract with CMK s.r.o., Slovakia was signed for conducting GDMS analysis. Organization for rod testing by FZ pulling was also chosen. The only organization capable and willing to solve said task is IKZ Berlin, Germany

– According to requirements of new heated unit system for automatic alteration of electron beam heater parameters was created in order to sustain stable conditions of polycrystalline rod growth.