Abstract: A melter assembly supplies a charge of molten source material to a crystal forming apparatus for use in forming crystalline bodies. The melter assembly comprises a housing and a crucible located in the housing. A heater is disposed relative to the crucible for melting solid source material received in the crucible. The crucible has a nozzle to control the flow of molten source material such that a directed flow of molten source material can be supplied to the crystal forming apparatus at a selected flow rate.

Abstract: A method of servicing multiple crystal forming apparatus with a single melter assembly is provided. The method includes the steps of positioning the melter assembly relative to a first crystal forming apparatus for delivering molten silicon to a crucible of the first apparatus. A heater in the melter assembly is operated to melt source material in a melting crucible. A stream of molten source material is delivered from the melter assembly to the first crystal forming apparatus. The melter assembly is positioned relative to a second crystal forming apparatus for delivering molten silicon to a crucible of the second apparatus. A stream of molten source material is transferred from the melter assembly to the second crystal forming apparatus.

Abstract: A method of charging a crystal forming apparatus with molten source material is provided. The method includes the steps of positioning a melter assembly relative to the crystal forming apparatus for delivering molten silicon to a crucible of the apparatus. An upper heating coil in the melter assembly is operated to melt source material in a melting crucible. A lower heating coil in the melter assembly is operated to allow molten source material to flow through an orifice of the melter assembly to deliver a stream of molten source material to the crucible of the crystal forming apparatus. The invention is also directed to a method of charging a crystal puller with molten silicon including the step of removing an upper housing of the crystal puller defining a pulling chamber from a lower housing of the crystal puller defining a growth chamber and attaching the lower housing in place of the upper housing.

Abstract: A process for controlling the amount of insoluble gas trapped by a silicon melt is disclosed. After a crucible is charged with polycrystalline silicon, a gas comprising at least about 10% of a gas having a high solubility in silicon is used as the purging gas for a period of time during melting. After the polycrystalline silicon charge has completely melted, the purge gas may be switched to a conventional argon purge. Utilizing a purge gas highly soluble in silicon for a period of time during the melting process reduces the amount of insoluble gases trapped in the charge and, hence, the amount of insoluble gases grown into the crystal that form defects on sliced wafers.

Abstract: A process for preparing a silicon melt in a crucible for use in growing a single crystal silicon ingot by the Czochralski method. The crucible is first loaded with chunk polycrystalline silicon and heated to partially melt the load. Granular polycrystalline silicon is then fed onto the exposed unmelted chunk polycrystalline silicon to complete the charge of silicon in the crucible. The granular polycrystalline silicon is intermittently delivered using a plurality of alternating on-periods and off-periods. During each on-period, granular polycrystalline silicon is flowed through a feed device that directs the granular polycrystalline silicon onto the unmelted chunk polycrystalline silicon. During each off-period, the flow of the granular polycrystalline silicon is interrupted. The loaded chunk polycrystalline silicon and the fed granular polycrystalline silicon are melted to form the silicon melt.

Abstract: A process for preparing doped molten silicon for use in a single silicon crystal growing process is disclosed. Polysilicon is doped with barium and melted in a silica crucible containing less than about 0.5% gases insoluble in silicon. During melting and throughout the crystal growing process the barium acts as a devitrification promoter and creates a layer of devitrified silica on the inside crucible surface in contact with the melt resulting in a lower level of contaminants in the melt and grown crystal.

Abstract: A process for preparing strontium doped molten silicon for use in a single silicon crystal growing process is disclosed. Polysilicon is doped strontium and melted in a silica crucible. During melting and throughout the crystal growing process the strontium acts as a devitrification promoter and creates a layer of devitrified silica on the inside crucible surface in contact with the melt resulting in a lower level of contaminants in the melt and grown crystal.

Abstract: A process for controlling the amount of insoluble gas trapped by a silicon melt is disclosed. After a crucible is charged with polycrystalline silicon, a gas comprising at least about 10% of a gas having a high solubility in silicon is used as the purging gas for a period of time during melting. After the polycrystalline silicon charge has completely melted, the purge gas may be switched to a conventional argon purge. Utilizing a purge gas highly soluble in silicon for a period of time during the melting process reduces the amount of insoluble gases trapped in the charge and, hence, the amount of insoluble gases grown into the crystal that form defects on sliced wafers.

Abstract: A process for preparing doped molten silicon for use in a single silicon crystal growing process is disclosed. Polysilicon is doped with barium and melted in a silica crucible containing less than about 0.5% gases insoluble in silicon. During melting and throughout the crystal growing process the barium acts as a devitrification promoter and creates a layer of devitrified silica on the inside crucible surface in contact with the melt resulting in a lower level of contaminants in the melt and grown crystal.

Abstract: A process for preparing a silicon melt from a polysilicon charge, for use in the production of single crystal silicon ingots by the Czochralski method, in a crucible which has a bottom, a sidewall formation, a centerline which is substantially parallel to the sidewall formation and which intersects a geometric centerpoint of the bottom, and a radius extending from the centerline to the sidewall formation. In the process, the crucible is loaded with chunk polysilicon to form a charge having a bowl-like shape, wherein initially the load generally slopes radially upwardly and outwardly from the centerline toward the sidewall formation to an apex and then slopes generally downwardly and outwardly from the apex to the sidewall formation. The bowl-shaped chunk polysilicon charge is heated to form a partially melted charge, and granular polysilicon is fed onto the partially melted charge to form a mixed charge of chunk and granular polysilicon.

Abstract: A quartz crucible for use in the preparation of silicon crystals substantially free from crystal void defects and a process for its preparation are disclosed. The crucible is prepared by introducing quartz powder into a rotating mould in an atmosphere containing less than about 0.5% insoluble gases such as argon. The quartz powder accumulates along the inner surface of the mould, and is subsequently heated to fuse the quartz powder to produce the crucible. The gases contained in the bubbles in the resulting crucible are comprised of less than about 0.5% insoluble gases.