Abstract: An improved process for contacting hydrogen gas and tetrachlorosilane in a reactor comprising a pressurizable shell having located therein a reaction vessel forming a substantially closed inner chamber for reacting the hydrogen gas with the tetrachlorosilane. The improvement comprises feeding to an outer chamber between the pressurizable shell and the reaction vessel a gas or gaseous mixture having a chlorine to silicon molar ratio greater than about 3.5. The improvement reduces the concentration of hydrogen and tetrachlorosilane in the outer chamber that results from leakage of these gases from the substantially closed inner chamber and the detrimental reactions associated with such leakage on structural elements and performance of the reactor.

Abstract: There is described a method of closing ends of silicon tubular bodies in which the tube end to be closed is dipped into melt of silicon maintained at substantially the melting temperature of silicon until the end of the tube is heated to the melting point and then withdrawing the tube from the melt with melt temperature sufficiently low to cause freezing of molten silicon at tube end and at temperature and speed sufficient to cause decreasing diameter of the freezing silicon until the desired diameter reduction or closure is obtained and then breaking contact with the melt. Additionally, surface portions may be machined after withdrawal from the melt to allow connections to be made.