# US 12,110,609 B2 · Methods for forming a single crystal silicon ingot with reduced crucible erosion > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,110,609 B2 - Document ID: US12110609B2 - Status: Granted - Kind: B2 - Application number: 17/152,993 - Filed: 2021-01-20 - Published: 2022-05-12 - Granted: 2024-10-08 - Earliest claimed: 2020-11-11 - Assignees: GlobalWafers Co., Ltd. - Applicants: GlobalWafers Co., Ltd. - Inventors: Richard Joseph Phillips; Salvador Zepeda - Web page: https://patentgrep.com/patent/US12110609B2 ## CPC - C30B 15/10: Crucibles or containers for supporting the melt - C30B 15/02: adding crystallising materials or reactants forming it in situ to the melt - C30B 15/30: Mechanisms for rotating or moving either the melt or the crystal (flotation methods C30B15/28) - C30B 29/06: Silicon - C30B: SINGLE-CRYSTAL GROWTH (by using ultra-high pressure, e.g. for the formation of diamonds, B01J3/06); UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL (zone-refining of metals or alloys C22B); PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (casting of metals, casting of other substances by the same processes or devices B22D; working of plastics B29; modifying the physical structure of metals or alloys C21D, C22F); SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (for producing semiconductor devices or parts thereof H10); APPARATUS THEREFOR ## Abstract Methods for forming a single crystal silicon ingot with reduced crucible erosion are disclosed. Solid-phase quartz is added to the melt to reduce erosion at the crucible-melt surface interface. The quartz may be synthetic quartz such as synthetic quartz rods. The quartz may be disposed near the crucible-melt surface interface. Quartz dissolves and suppresses the amount of quartz that dissolves from the crucible at the crucible-melt surface interface. ## Claims ### Claim 1 A method for forming a single crystal silicon ingot comprising: adding solid-phase polycrystalline silicon to a crucible having a sidewall and a bottom; heating the polycrystalline silicon to form a silicon melt having a surface; contacting the silicon melt with a seed crystal; withdrawing the seed crystal from the silicon melt to form a silicon ingot; adding solid-phase synthetic quartz to the melt, the synthetic quartz being made by melting synthetic sand and extruding the melt of synthetic sand; and at least partially dissolving the synthetic quartz, the synthetic quartz abutting the crucible sidewall at the surface of the melt when being dissolved, the surface of the melt being unobstructed between the ingot and the synthetic quartz, there being a gap between the synthetic quartz and ingot after addition of all synthetic quartz to the melt. ### Claim 2 (depends on 1) The method as set forth in claim 1 wherein the synthetic quartz contains 5.0 ppmw or less impurities. ### Claim 3 (depends on 1) The method as set forth in claim 1 wherein the crucible comprises a quartz base layer and a synthetic quartz liner disposed on the quartz base layer. ### Claim 4 (depends on 1) The method as set forth in claim 1 wherein the synthetic quartz is disposed about the entire circumference of the crucible at the surface of the melt. ### Claim 5 (depends on 1) The method as set forth in claim 1 comprising rotating the crucible, wherein centrifugal force caused by rotation of the crucible causes the synthetic quartz to abut the crucible sidewall. ### Claim 6 (depends on 1) The method as set forth in claim 1 wherein the synthetic quartz is added before growth of the silicon ingot. ### Claim 7 (depends on 1) The method as set forth in claim 1 wherein synthetic quartz is added during ingot growth. ### Claim 8 (depends on 1) The method as set forth in claim 1 wherein synthetic quartz is added no more than once to the melt. ### Claim 9 (depends on 1) The method as set forth in claim 1 wherein synthetic quartz is added to the melt in two or more cycles. ### Claim 10 (depends on 1) The method as set forth in claim 1 wherein the ingot is grown in a batch Czochralski process and polycrystalline silicon is not added to the melt during ingot growth. ### Claim 11 (depends on 1) The method as set forth in claim 1 wherein the ingot is grown in a continuous Czochralski process in which polycrystalline silicon is added to the melt during ingot growth. ### Claim 12 A method for forming a single crystal silicon ingot comprising: adding solid-phase polycrystalline silicon to a crucible having a sidewall and a bottom; heating the polycrystalline silicon to form a silicon melt; contacting the silicon melt with a seed crystal; withdrawing the seed crystal from the silicon melt to form a silicon ingot, the ingot being grown in a batch Czochralski process with polycrystalline silicon not being added to the melt during ingot growth; adding solid-phase quartz to the melt such that solid-phase quartz only extends partially across a surface of the silicon melt; and at least partially dissolving the quartz to reduce dissolution of the crucible, the quartz abutting the entire circumference of the crucible at the surface of the melt when being dissolved, the surface of the melt being unobstructed between the ingot and the solid-phase quartz. ### Claim 13 (depends on 12) The method as set forth in claim 12 wherein the quartz is shaped as a rod, tube, sphere or has an irregular shape. ### Claim 14 (depends on 12) The method as set forth in claim 12 wherein the quartz contains 0.7 ppmw or less impurities. ### Claim 15 (depends on 12) The method as set forth in claim 12 wherein the crucible comprises a quartz base layer and a synthetic quartz liner disposed on the quartz base layer. ### Claim 16 (depends on 12) The method as set forth in claim 12 comprising rotating the crucible, wherein centrifugal force caused by rotation of the crucible causes the solid-phase quartz to abut the crucible sidewall. ### Claim 17 (depends on 12) The method as set forth in claim 12 wherein the solid-phase quartz are added before growth of the silicon ingot or during ingot growth.