Crucibles having anchors and methods for producing and using same
OwnerRichard Joseph Phillips, William Luterinventors
Life of this patent
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Abstract
Crucibles for holding a silicon melt are disclosed. The crucible includes a crucible body having a floor and a sidewall extending up from the floor. The floor and sidewall define a cavity for holding the silicon melt. The crucible body has an inner surface and an outer surface. One or more anchors extend into the cavity from the inner surface of the floor. Methods for forming a single crystal silicon ingot are also disclosed. The anchors may resist the buoyancy of a solid layer of silicon in double-layer Czochralski methods.
Claims20
A method for producing a crucible, the method comprising:
- providing a crucible body having a floor and a sidewall extending up from the floor, the floor and sidewall defining an inner cavity for holding a silicon melt, the crucible body having an inner surface and an outer surface;
- and
- preparing a silica bonding slip by adding particulate silica to a liquid carrier;
- applying the silica bonding slip to the inner surface of the crucible body to form a wetted surface;
- positioning one or more anchors in the inner cavity such that the one or more anchors are disposed on the wetted surface of the crucible body;
- and
- heating the crucible body and the one or more anchors disposed in the inner cavity to bond the one or more anchors to the inner surface of the crucible body.
A method for forming a single crystal silicon ingot comprising:
- adding an initial charge of polycrystalline silicon to a crucible, the crucible comprising:
- a crucible body having a floor and a sidewall extending up from the floor, the floor and sidewall defining a cavity for holding a silicon melt, the crucible body having an inner surface and an outer surface;
- and
- one or more anchors that extend into the cavity from the inner surface of the floor;
- heating the initial charge of polycrystalline silicon to cause the silicon melt to form in the crucible;
- cooling the silicon melt to cause a region of the silicon melt adjacent the floor of the crucible to solidify such that a solid layer is formed between the anchors;
- contacting a silicon seed crystal with the silicon melt;
- and
- withdrawing the silicon seed crystal to grow a single crystal silicon ingot.
Dependencies are inferred from the claim text.