A core wire holder 3 attached on an electrode 2 placed on a bottom panel of a device 20 for producing silicon by Siemens process includes a silicon core wire holding portion 9 being generally circular truncated cone-shaped, and holding and energizing a silicon core wire 4. The silicon core wire holding portion 9 includes a generally circular truncated cone having an upper surface formed with a silicon core wire insertion hole 7 for holding the silicon core wire 4, and the silicon core wire holding portion 9 includes an upper surface and a side surface, which form a ridge having a curved surface and serving as a chamfered portion 8.

A core wire holder 3 attached on an electrode 2 placed on a bottom panel of a device 20 for producing silicon by Siemens process includes a silicon core wire holding portion 9 being generally circular truncated cone-shaped, and holding and energizing a silicon core wire 4. The silicon core wire holding portion 9 includes a generally circular truncated cone having an upper surface formed with a silicon core wire insertion hole 7 for holding the silicon core wire 4, and the silicon core wire holding portion 9 includes an upper surface and a side surface, which form a ridge having a curved surface and serving as a chamfered portion 8.

For evaluating a polycrystalline silicon rod to be used as a raw material for production of FZ Si single crystals, novel evaluation values (values of characteristics×amount of crystals) including the amount of crystals grown in the growth direction (radial direction) are defined and the homogeneity in crystal characteristics in the growth direction (radial direction) is evaluated. Specifically, the homogeneity of the polycrystalline rod is evaluated by sampling a plurality of specimen plates each having, as a principal plane thereof, a cross-section perpendicular to a radial direction of the polycrystalline rod grown by a Siemens method at equal intervals in the radial direction, determining values of characteristics of the crystals of the specimen plates by measurements, and by using evaluation values obtained by multiplying amounts of the crystals (relative amounts of the crystals) at sites where the specimen plates have been sampled by the values of the crystal characteristics.

For evaluating a polycrystalline silicon rod to be used as a raw material for production of FZ Si single crystals, novel evaluation values (values of characteristics×amount of crystals) including the amount of crystals grown in the growth direction (radial direction) are defined and the homogeneity in crystal characteristics in the growth direction (radial direction) is evaluated. Specifically, the homogeneity of the polycrystalline rod is evaluated by sampling a plurality of specimen plates each having, as a principal plane thereof, a cross-section perpendicular to a radial direction of the polycrystalline rod grown by a Siemens method at equal intervals in the radial direction, determining values of characteristics of the crystals of the specimen plates by measurements, and by using evaluation values obtained by multiplying amounts of the crystals (relative amounts of the crystals) at sites where the specimen plates have been sampled by the values of the crystal characteristics.

An apparatus for manufacturing polysilicon rod by a Siemens method has a base plate 20; and a holding body 100 provided on the base plate 20 so as to be movable in a horizontal direction and electrically connect between a core wire holder 1 and an electrode 4. The holding body 100 is configured to rotatably hold the core wire holder 1 with respect to the base plate 20.

An apparatus for manufacturing polysilicon rod by a Siemens method has a base plate 20; and a holding body 100 provided on the base plate 20 so as to be movable in a horizontal direction and electrically connect between a core wire holder 1 and an electrode 4. The holding body 100 is configured to rotatably hold the core wire holder 1 with respect to the base plate 20.

The invention relates to a process for preparing polycrystalline silicon, comprising introducing a reaction gas containing hydrogen and silane and/or halogen silane into a reactor, wherein the reactor comprises at least one heated carrier body, on which elementary silicon has been deposited by means of pyrolysis, forming the polycrystalline silicon. In a continuous process, waste gas is led out of the reactor and hydrogen recovered from said waste gas is fed to the reactor again as circulating gas. The circulating gas has a nitrogen content of less than 1000 ppmv. The invention further relates to polycrystalline silicon having a nitrogen component of less than 2 ppba.

The invention relates to a process for preparing polycrystalline silicon, comprising introducing a reaction gas containing hydrogen and silane and/or halogen silane into a reactor, wherein the reactor comprises at least one heated carrier body, on which elementary silicon has been deposited by means of pyrolysis, forming the polycrystalline silicon. In a continuous process, waste gas is led out of the reactor and hydrogen recovered from said waste gas is fed to the reactor again as circulating gas. The circulating gas has a nitrogen content of less than 1000 ppmv. The invention further relates to polycrystalline silicon having a nitrogen component of less than 2 ppba.

A polymer inactivation method for a polycrystalline silicon manufacturing device, wherein the polymer byproducts are treated and additionally treated in a manner that controls the rate of reaction. The polymer byproducts are treated with a first inert gas under partial vacuum and a second oxygen containing gas to convert the polymer byproducts. The reaction rate can be controlled by regulating the fill pressure of reactant gas, controlling the amount of oxygen in the reactant gas, and stripping of the raw polymer with heat and or a vacuum. The solid byproduct remaining after treating the polymer, which is predominately silicon suboxides (SiO.sub.x) and silicon dioxide (SiO.sub.2), is inert and is easily removed.

A polymer inactivation method for a polycrystalline silicon manufacturing device, wherein the polymer byproducts are treated and additionally treated in a manner that controls the rate of reaction. The polymer byproducts are treated with a first inert gas under partial vacuum and a second oxygen containing gas to convert the polymer byproducts. The reaction rate can be controlled by regulating the fill pressure of reactant gas, controlling the amount of oxygen in the reactant gas, and stripping of the raw polymer with heat and or a vacuum. The solid byproduct remaining after treating the polymer, which is predominately silicon suboxides (SiO.sub.x) and silicon dioxide (SiO.sub.2), is inert and is easily removed.