| Among the several known processes of semiconductor-grade silicon production, the hydrogen reduction of trichlosilane (TCS) is found to be the most convenient and economical method. In this study of high purity silicon production, the open tube flow process is used to reduce TCS with hydrogen. 99.9% pure TCS, manufactured by Ventron, is distilled for the starting material in the reduction. The distilled TCS is vaporized by bubbling at 0℃ with small quantity of hydrogen in a quartz tube. The resultant yield is compared with the theoretical one calculated thermodynamically. The yield of silicon is 60-70% at the optimum condition of 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 product is determined to be higher than 99.999%. |
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