# US 7,608,145 B2 · Method and apparatus of growing silicon single crystal and silicon wafer fabricated thereby > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,608,145 B2 - Document ID: US7608145B2 - Status: Granted - Kind: B2 - Application number: 11/773,669 - Filed: 2007-07-05 - Published: 2008-03-06 - Granted: 2009-10-27 - Earliest claimed: 2004-11-23 - Assignees: Siltron Inc. - Inventors: Hyon-Jong Cho - Web page: https://patentgrep.com/patent/US7608145B2 ## CPC - C30B 15/203: {the relationship of pull rate (v) to axial thermal gradient (G)} - C30B 15/00: Single-crystal growth by pulling from a melt, e.g. Czochralski method (under a protective fluid C30B27/00) - C30B 15/14: Heating of the melt or the crystallised materials - C30B 15/20: Controlling or regulating (controlling or regulating in general G05) - C30B 29/06: Silicon - Y10S 117/917: Magnetic - Y10T 117/1068: including heating or cooling details [e.g., shield configuration] - Y10T 117/1088: including heating or cooling details - 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 - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract Disclosed is a method of fabrication of high quality silicon single crystal at high growth rate. The method grows silicon single crystal from silicon melt by Czochralski method, wherein the silicon single crystal is grown according to conditions that the silicon melt has an axial temperature gradient determined according to an equation, {(ΔTmax−ΔTmin)/ΔTmin}×100≦10, wherein ΔTmax is a maximum axial temperature gradient of the silicon melt and ΔTmin is a minimum axial temperature gradient of the silicon melt, when the axial temperature gradient is measured along an axis parallel to a radial direction of the silicon single crystal. ## Claims ### Claim 1 A method of growing a silicon single crystal from silicon melt by Czochralski method, wherein the silicon single crystal is grown according to conditions that the silicon melt has an axial temperature gradient determined according to an equation, {(ΔTmax−ΔTmin)/ΔTmin}×100≦10, wherein ΔTmax is a maximum axial temperature gradient of the silicon melt and ΔTmin is a minimum axial temperature gradient of the silicon melt, when the temperature gradient is measured along an axis parallel to a radial direction of the silicon single crystal. ### Claim 2 (depends on 1) The method according to claim 1, wherein the axial temperature gradient is a mean axial temperature gradient. ### Claim 3 (depends on 1) The method according to claim 1, wherein the axis is a central axis passing through the center of the silicon single crystal. ### Claim 4 (depends on 1) The method according to claim 1, wherein, when the temperature of the silicon melt is measured along an axis parallel to a longitudinal direction of the silicon single crystal, the silicon single crystal is grown according to conditions that the temperature of the silicon melt measured starting with an interface between the silicon melt and the single crystal rises gradually up to a hottest point and then descends gradually as getting away from the silicon single crystal, and the rising temperature gradient of the melt is kept larger than the descending temperature gradient of the melt. ### Claim 5 (depends on 4) The method according to claim 4, wherein the temperature gradient of the silicon melt measured along the axis parallel to the radial direction of the single crystal is taken a portion of the silicon melt ranging from the interface to the hottest point. ### Claim 6 (depends on 4) The method according to claim 4, wherein the axis parallel to the longitudinal direction of the single crystal passes through the center of the silicon single crystal. ### Claim 7 (depends on 4) The method according to claim 4, wherein the hottest point is positioned in a portion of the silicon melt corresponding to ⅕ to ⅔ of the total depth of the silicon melt from the surface. ### Claim 8 (depends on 7) The method according to claim 7, wherein the hottest point is positioned in a portion of the silicon melt corresponding to ⅓ to ½ of the total depth of the silicon melt from the surface. ### Claim 9 (depends on 1) The method according to claim 1, wherein the temperature gradient of the silicon melt measured along the axis parallel to the radial direction of the single crystal is taken from a portion of the melt positioned under the single crystal. ### Claim 10 (depends on 1) The method according to claim 1, wherein the silicon single crystal is grown according to an equation: 3≦Ln[Vs/Vc]≦5, wherein Vc is a rotation speed of a crucible containing the silicon melt and Vs is the rotation of the silicon single crystal. ### Claim 11 (depends on 1) The method according to claim 1, wherein the silicon single crystal is grown from the silicon melt under magnetic field. ### Claim 12 (depends on 11) The method according to claim 11, wherein the magnetic field is applied to the silicon melt in a direction vertical or horizontal to the longitudinal direction of the single crystal, or in CUSP. ### Claim 13 (depends on 11) The method according to claim 11, wherein a heater is provided at sides of the silicon melt to heat the silicon melt so that heat generation in a portion of the silicon melt corresponding to ⅕ to ⅔ of the total depth of the silicon melt from the surface is increased over surrounding portions of the silicon melt. ### Claim 14 (depends on 1) The method according to claim 1, wherein a heater is provided at sides of the silicon melt to heat the silicon melt so that heat generation in a portion of the silicon melt corresponding to ⅕ to ⅔ of the total depth of the silicon melt from the surface is increased over surrounding portions of the silicon melt. ### Claim 15 A method of growing silicon single crystal from silicon melt by Czochraiski method, wherein the silicon single crystal is grown according to an equation: 3≦Ln[Vs/Vc]55, wherein Vc is a rotation speed of a crucible containing the silicon melt and Vs is the rotation of the silicon single crystal.