Measurement technique for instant temperature distribution in the melt of large-scale Czochralski silicon growth

In the current work measurement method has been developed that allows to get instant temperature distributions in the melt of large diameter Czochralski silicon single crystal growth. Measurements of the velocity of the convective melt flows are also provided. Nowadays single-crystalline silicon is mainly used in electronic industry for the IC's production as a substrate material. Single crystals are pulled out from the melt by the Czochralski method (CZ). The quality of the single crystals is determined by various factors, but the most important among them are hydrodynamic flows due to non-stationary convection. The morphology of such flows determines radial and axial distribution of dopands in the growing crystal. The control of unstable convection is the most important problem in the modern Czochralski technology. The solution (that is state-of-art today) is the use of external magnetic fields (AC or DC) that allows to influence or damp the unstable motion of electrically conducting Si melt. These processes are very complex and for further optimisation of the CZ technology, especially in the context of transition to larger crystal diameters, it is necessary to conduct scientific investigations of the hydrodynamics and heat transfer phenomena in the CZ melt. Liquid silicon is a very aggressive material, therefore, temperature and velocity measurements in the melt are very expensive or practically impossible. The possibility of temperature field and distributions of the melt velocity investigation is provided in this work by means of a physical simulation technique and by a developed multi-channel acquisition system that allow to get instant temperature distributions in the whole cross-section of the melt and to study not only stationary temperature distributions in the melt, but, also to look after the temperature field evolution in time. That will allow to investigate various hydrodynamical instabilities in the melt. This work was carried out at the Institute of Physics of University of Latvia in the frame of grants of the Science Council of Latvia as well as in collaboration with one of the leader company in the field of the single silicon production - Wacker Sitronic AG (Germany).Abstract in English, Latvian, RussianAvailable from Latvian Academic Library / LAL - Latvian Academic LibrarySIGLELVLatvi