Elza Khutsishvili
Ferdinand Tavadze Institute of Metallurgy and Materials Science, Georgia
Title: Impurities effective distribution coefficient in Si at pulling from MG-Si melt
Biography
Biography: Elza Khutsishvili
Abstract
Silicon is still the basic active component of modern high-performance semiconductor devices, especially for the terrestrial photo energetics. However further development of Si producing is held back by high cost price because of laborious and quite complicated technologies and application of dangerous materials. In this connection the search of other environmentally clean technologies of Si producing is very actual. In given work ecologically pure technology of normal directional crystallization and pulling from melt have been applied for direct purification of metallurgical Si. Initial metallurgical grade Si was 98%Si purity in mass with 2% of collection of unwanted impurities. Investigations of Si purification processes by normal directional crystallization with multiple remelting show, that the most effect of purification is achieved after third remelting of Si. As in the previous exsperiment metallurgical Si has been purified practically from majority of impurities by crystal pulling too. Data of effective coefficient of distribution of major impurities in Si satisfy to k0 ≤ k ≤1 inequality. Different mechanisms or their combination of . the purification processes of Si from impurities and peculiarities of impurities effective distribution coefficient in Si at pulling from MG-Si melt are discussed.