John D. Holder - Lake St. Louis MO Steven Joslin - St. Peters MO Hariprasad Sreedharamurthy - Maryland Heights MO John Lhamon - St. Peters MO
Assignee:
MEMC Electronic Materials, Inc. - St. Peters MO
International Classification:
C30B 1500
US Classification:
117 14, 382206
Abstract:
A method and system for determining polycrystalline silicon chunk size for use with a Czochralski silicon growing process. Polycrystalline silicon chunks are arranged on a measuring background. A camera captures an image of the chunks. An image processor processes the image and determines the dimensions of the chunks based on the captured image. A size parameter associated with the chunks is determined.
Lee W. Ferry - St. Charles MO Richard G. Schrenker - Chesterfield MO Hariprasad Sreedharamurthy - Ballwin MO
Assignee:
MEMC Electronic Materials, Inc. - St. Peters MO
International Classification:
C30B 3500
US Classification:
117217, 117218, 117222, 117900
Abstract:
A heat shield assembly is disclosed for use in a crystal puller for growing a monocrystalline ingot from molten semiconductor source material. The heat shield assembly has a central opening sized and shaped for surrounding the ingot as the ingot is pulled from the molten source material. In one aspect, the heat shield assembly includes a multi-sectioned outer shield and a multi-sectioned inner shield. The sections of at least one of the inner and outer shields may be releasably connected to one another so that, in the event a section is damaged, the sections may be separated to allow replacement with an undamaged section. In another aspect the heat shield assembly includes an upper section and a lower section extending generally downward from the upper section toward the molten material. The lower section has a height equal to at least about 33% of a height of the heat shield assembly.
Hariprasad Sreedharamurthy - Ballwin MO, US Mohsen Banan - Grover MO, US
Assignee:
MEMC Electronic Materials, Inc. - St. Peters MO
International Classification:
C30B015/36 C30B015/00
US Classification:
117 13, 117 35, 117902, 117931, 117932
Abstract:
The present invention provides for a process for preparing a single crystal silicon ingot by the Czochralski method. The process comprises selecting a seed crystal for Czochralski growth wherein the seed crystal comprises vacancy dominated single crystal silicon.
Systems And Methods For Measuring And Reducing Dust In Granular Material
John D. Holder - Lake St. Louis MO, US Hariprasad Sreedharamurthy - Ballwin MO, US John D. Hilker - St. Charles MO, US
Assignee:
MEMC Electronic Materials, Inc. - St. Peters MO
International Classification:
C30B 15/02
US Classification:
117 31, 117 33, 117 34, 117213, 117217
Abstract:
The invention is directed to apparatus and methods for measuring and for reducing dust in granular polysilicon. In one aspect, a system includes a process vessel having a vacuum port for pulling dust from the polysilicon. Another system of the invention includes a baffle tube for receiving a polysilicon flow. A measuring system includes a manifold and filter for separating and measuring the dust from a flow of polysilicon. The invention is also directed to methods of using the systems, to methods of manufacturing and packaging granular polysilicon, and to a supply of granular polysilicon.
Controlling A Melt-Solid Interface Shape Of A Growing Silicon Crystal Using An Unbalanced Magnetic Field And Iso-Rotation
Hariprasad Sreedharamurthy - Ballwin MO, US Milind Kulkarni - St. Louis MO, US Richard G. Schrenker - Chesterfield MO, US Joseph C. Holzer - St. Peters MO, US Harold W. Korb - Chesterfield MO, US
Assignee:
MEMC Electronic Materials, Inc. - St. Peters MO
International Classification:
C30B 15/02
US Classification:
117 13, 117 17, 117 18, 117 30
Abstract:
A system for growing silicon crystals that facilitates controlling a shape of a melt-solid interface is described. The crystal growing system includes a heated crucible including a semiconductor melt from which a monocrystalline ingot is grown according to a Czochralski process. The ingot is grown on a seed crystal pulled from the melt. The method includes applying an unbalanced cusped magnetic field to the melt, and rotating the ingot and the crucible in the same direction while the ingot is being pulled from the melt.
Generating A Pumping Force In A Silicon Melt By Applying A Time-Varying Magnetic Field
Hariprasad Sreedharamurthy - Ballwin MO, US Milind Kulkarni - St. Louis MO, US Harold W. Korb - Chesterfield MO, US
Assignee:
MEMC Electronic Materials, Inc. - St. Peters MO
International Classification:
C30B 30/04
US Classification:
117 32, 117 13, 117 14, 117 15, 117 30
Abstract:
Controlling crystal growth in a crystal growing system is described. The crystal growing system includes a heated crucible including a semiconductor melt from which a monocrystalline ingot is grown according to a Czochralski and the ingot is grown on a seed crystal pulled from the melt. The method includes applying a cusped magnetic field to the melt by supplying an upper coil with a first direct current (I) and supplying a lower coil with a second direct current (I). The method also includes supplying the upper coil with a first alternating current (I) and supplying the lower coil with a second alternating current (I) to generate a time-varying magnetic field, wherein the time-varying magnetic field generates a pumping force in the semiconductor melt.
Crystal Puller And Method For Growing Single Crystal Semiconductor Material
A crystal puller and method for growing single crystal semiconductor material having a susceptor assembly that includes a susceptor disposed in the crystal puller for receiving and holding a crucible. The side wall of the susceptor is in generally radially opposed relationship with the side wall of the crucible. A sealing member of the assembly is adapted for close contact relationship with the crucible side wall and the susceptor side wall to generally seal between the crucible and the susceptor any gaseous product resulting from a reaction of the crucible with the susceptor against escape from between the crucible and the susceptor, thereby inhibiting the reaction of the crucible with the susceptor.
Apparatus And Process For The Preparation Of Low-Iron Single Crystal Silicon Substantially Free Of Agglomerated Intrinsic Point Defects
A method and apparatus for producing silicon single crystals with reduced iron contamination is disclosed. The apparatus contains at least one structural component constructed of a graphite substrate and a silicon carbide protective layer covering the surface of the substrate that is exposed to the atmosphere of the growth chamber. The graphite substrate has a concentration of iron no greater than about 1.5*10atoms/cmand the silicon carbide protective layer has a concentration of iron no greater than about 1.0*10atoms/cm.