Abstract: A crystal-pulling apparatus for pulling and growing a monocrystalline silicon ingot comprises a quartz crucible placed in a chamber and containing a silicon melt from which a monocrystalline silicon ingot will be pulled, a graphite crucible container to support the quartz crucible by surrounding the outer circumferential surface and external base surface of crucible, and a heater provided around the outer circumferential surface of the crucible container to heat the silicon melt. This apparatus further comprises a spacer having a top surface whose area is smaller than the base area of the quartz crucible and having a melting point higher than that of silicon, is inserted between the base of the quartz crucible and the base of the crucible container while the monocrystalline silicon ingot is pulled.

Abstract: A delivery system and method for providing a gaseous chemical is provided. The system comprises a single bubbler 12 having a chamber 13 for containing a liquid chemical, at least one inlet tube 14 for providing a carrier gas to said chamber, and one outlet tube 16 for providing the gaseous chemical. A liquid chemical supply line 25 conveys the liquid chemical to said chamber. A bubbler is in contact with weight measuring device 24 for weighing the bubbler and generating an output signal responsive to the measured weight. A liquid chemical controller 20 is operatively coupled to said bubbler and said supply line for filling and continuously maintaining a preselected level of the liquid chemical in said chamber responsive to said output signal.