| Among the several known processes of semiconductorgrade silicon production, the hydrogen reduction of trichlorosilane (TCS) is found to be the most convenient and economical method. In this study of high purity silicon production, the tube flow process is used to redus TCS with hydrogen. The 99.9% pure TCS, manufactured by Ventron, is distilled for the starting material in the reduction. The distilled TCS is vaporized by bubbling with small quantity of hydrogen in a glass tube at 0℃. The resultant yield is especially compared with the theoretical one calculated thermodynamically. The yield of silicon is 60-70% at the optimum condition of 1050-1100℃ reaction temperature and 60-100 mole ratio of hydrogen to TCS. Surface of the deposited silicon, a polycrystalline dense mass of lustrous appearance, is treated with hydrofluoric acid. By the emission spectroscopy the purity of silicon thus produced is determined to be higher than 99.999%. |
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