Краткое описание

Laser Induced Breakdown Spectroscopy is a new analytical method permitting in less than 10.10⁻⁶ second to qualify by atomic emission spectroscopy the composition of every kind of material without any sampling. The high sensibility of the technique (10⁻⁷g/g) gives the possibility to qualify the purity of the material, its defects or any kind of pollutant from the crucible or impurity from the raw material. We have developed this technique for three kinds of silicon materials; firstly metallurgical grade silicon, the raw material, secondly this previous silicon after its purification by an RF plasma process, at last the photovoltaic grade silicon to evaluate the efficiency of the plasma process purification. First analysis of photovoltaic and metallurgical grade silicon (raw material) gives references of two degrees of silicon purity. After the plasma treatment we analyze the surface and the bulk of the treated sample to understand diffusion mechanisms of impurities in the liquid material during the plasma treatment.