# US 10,370,773 B2 · Process for manufacturing synthetic single crystal diamond material using a pressure driven growth process and a plurality of seed pads with each seed pad comprising a plurality of single crystal diamond seeds > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,370,773 B2 - Document ID: US10370773B2 - Status: Granted - Kind: B2 - Application number: 14/383,074 - Filed: 2013-03-13 - Published: 2015-01-29 - Granted: 2019-08-06 - Earliest claimed: 2012-03-15 - Assignees: Element Six Technologies Limited - Applicants: Element Six Technologies Limited - Inventors: Dietrich Borse; Eugen Gura; Carlton Nigel Dodge; Raymond Anthony Spits - Web page: https://patentgrep.com/patent/US10370773B2 ## CPC - C30B 9/00: Single-crystal growth from melt solutions using molten solvents (by normal or gradient freezing C30B11/00; by zone-melting C30B13/00; by crystal pulling C30B15/00; on immersed seed crystal C30B17/00; by liquid phase epitaxial growth C30B19/00; under a protective fluid C30B27/00) - B01J 3/067: {Presses using a plurality of pressing members working in different directions} - B01J 23/75: Cobalt - B01J 23/755: Nickel - B01J 23/8892: {Manganese} - B01J 2203/0625: Carbon - B01J 2203/068: Crystal growth - C30B 29/04: Diamond - 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 - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS ## Abstract A method for manufacturing a plurality of synthetic single crystal diamonds, the method comprising: forming a plurality of seed pads, each seed pad comprising a plurality of single crystal diamond seeds anchored to, or embedded in, an inert holder; loading a carbon source, a metal catalyst, and the plurality of seed pads into a capsule; loading the capsule into a high pressure high temperature (HPHT) press; and subjecting the capsule to a HPHT growth cycle to grow single crystal diamond material on the plurality of single crystal diamond seeds, the HPHT growth cycle comprising: initiating HPHT growth of single crystal diamond material on the plurality of single crystal diamond seeds by increasing pressure and temperature; maintaining HPHT growth of single crystal diamond material on the plurality of single crystal diamond seeds via a pressure driven growth process by controlling and maintaining pressure and temperature; and terminating HPHT growth of single crystal diamond material on the plurality of single crystal diamond seeds by reducing pressure and temperature, wherein the plurality of single crystal diamond seeds remain anchored to, or embedded in, the inert holders during the HPHT growth cycle. ## Claims ### Claim 1 A method for manufacturing a plurality of synthetic single crystal diamonds, the method comprising: forming a plurality of seed pads, each seed pad comprising a plurality of single crystal diamond seeds anchored to an inert holder; loading a carbon source, a metal catalyst, and the plurality of seed pads into a capsule, wherein the carbon source and the metal catalyst are mixed to form a reaction mixture comprising graphite in an amount in a range of from 16 to 35 wt. %, and at least a portion of the carbon source is located less than 0.1 mm from the single crystal diamond seeds; loading the capsule into a high pressure high temperature (HPHT) press; and subjecting the capsule to a HPHT growth cycle to grow single crystal diamond material on the plurality of single crystal diamond seeds, the HPHT growth cycle comprising: initiating HPHT growth of single crystal diamond material on the plurality of single crystal diamond seeds by increasing pressure and temperature; maintaining HPHT growth of single crystal diamond material on the plurality of single crystal diamond seeds via a pressure driven growth process by controlling and maintaining pressure and temperature for at least 20 hours; and terminating HPHT growth of single crystal diamond material on the plurality of single crystal diamond seeds by reducing pressure and temperature, wherein the plurality of single crystal diamond seeds remain anchored to the inert holders during the HPHT growth cycle, and wherein the inert holder comprises a ceramic material. ### Claim 2 (depends on 1) A method according to claim 1, wherein each seed pad comprises a number of single crystal diamond seeds in a range of from 8 to 3000 and/or wherein each seed pad comprises a density of single crystal diamond seeds in a range of from 0.3 to 45 seeds cm−2. ### Claim 3 (depends on 1) A method according to claim 1, wherein the capsule comprises a number of seed pads in a range of from 4 to 30. ### Claim 4 (depends on 1) A method according to claim 1, wherein the seeds pads are spaced apart within the capsule such that a distance between the seeds pads is selected to be in a range of from 1 to 10-times a height of the single crystal diamond material after terminating HPHT growth and/or wherein the seeds pads are spaced apart within the capsule such that a distance between the seeds pads is selected to be in a range of from 1.0 to 12 mm. ### Claim 5 (depends on 1) A method according to claim 1, wherein the carbon source material has a total impurity level no more than 0.1%-by weight. ### Claim 6 (depends on 1) A method according to claim 1, wherein the carbon source material has a surface area per gram in a range of from 0.001 m2/g to 10 m2/g. ### Claim 7 (depends on 1) A method according to claim 1, wherein the reaction mixture comprises powdered metal catalyst in an amount in the range of from 65% to 84% by weight prior to the HPHT growth cycle. ### Claim 8 (depends on 1) A method according to claim 1, wherein the initiating step comprises raising the pressure to a target starting value Ps which is below the Berman-Simon graphite/diamond thermodynamic phase stability line, raising the temperature to a value Tg which exceeds a eutectic temperature for the carbon source and the metal catalyst, holding the temperature and pressure for a time t, and then raising the pressure to a target starting value Pg for the maintaining step to initiate HPHT growth. ### Claim 9 (depends on 8) A method according to claim 8, wherein the time t is in a range of from 1 to 36000 seconds. ### Claim 10 (depends on 8) A method according to claim 8, wherein the temperature Tg is in a range of from 1070 Kelvin to 2470 Kelvin. ### Claim 11 (depends on 8) A method according to claim 8, wherein the pressure Ps is within 0.01 to 2.0 GPa of pressure Pg. ### Claim 12 (depends on 8) A method according to claim 8, wherein the pressure Pg is in a range of from 4.0 to 8.0 GPa. ### Claim 13 (depends on 8) A method according to claim 8, wherein the pressure is raised from Ps to Pg at a rate in a range of from 0.001 to 1.0 GPa per minute. ### Claim 14 (depends on 1) A method according to claim 1, wherein, during the maintaining step, a temperature difference between a top side and a bottom side of the capsule is maintained to be no more than 100 Kelvin. ### Claim 15 (depends on 1) A method according to claim 1, wherein, during the maintaining step, a temperature gradient between a top side and a bottom side of the capsule is maintained to be no more than 0.66 Kelvin mm−1. ### Claim 16 (depends on 1) A method according to claim 1, wherein during the maintaining step the press moves anvils inwards whereby a volume of the capsule reduces by an amount in a range of from 0.5% to 50% and/or wherein during the maintaining step the press moves anvils inwards by a combined distance in the range of from 1 mm to 100 mm. ### Claim 17 (depends on 1) A method according to claim 1, wherein during the maintaining step the temperature is decreased in a continuous or stepwise manner while maintaining growth of single crystal diamond material on the plurality of single crystal diamond seeds. ### Claim 18 (depends on 17) A method according to claim 17, wherein the temperature is decreased at a rate in a range of from 0.1 Kelvin/hour to 2 Kelvin/hour. ### Claim 19 (depends on 1) An apparatus configured to perform the method according to claim 1, the apparatus comprising: a capsule comprising a plurality of seed pads and reactants including a carbon source and a metal catalyst, wherein the reactants and seed pads are provided in alternating layers, and wherein each seed pad comprises a plurality of single crystal diamond seeds anchored to, or embedded in, an inert holder; and a HPHT press comprising a heating circuit configured to maintain a substantially uniform temperature throughout the capsule whereby diamond growth on the single crystal seeds is achieved via a pressure driven growth process. ### Claim 20 (depends on 1) A method according to claim 1, wherein at least a portion of the carbon source is located less than 0.05 mm from the single crystal diamond seeds.