# US 2014/0150713 A1 · Controlling doping of synthetic diamond material

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2014/0150713 A1
- Document ID: US20140150713A1
- Status: Published application
- Kind: A1
- Application number: 13/994,922
- Filed: 2011-12-14
- Published: 2014-06-05
- Earliest claimed: 2010-12-23
- Assignees: Element Six Limited
- Inventors: Steven Edward Coe; Jonathan James Wilman; Daniel James Twitchen; Geoffrey Alan Scarsbrook; John Robert Brandon; Christopher John Howard Wort; Matthew Lee Markham
- Web page: https://patentgrep.com/patent/US20140150713A1

## CPC

- C01B 32/25: Diamond
- C01B 32/26: Preparation (by using ultra-high pressure B01J3/06; by crystal growth C30B29/04)
- C23C 16/274: {using microwave discharges}
- C23C 16/278: {doping or introduction of a secondary phase in the diamond}
- C30B 25/02: Epitaxial-layer growth
- C30B 25/14: Feed and outlet means for the gases; Modifying the flow of the reactive gases
- C30B 25/165: {the flow of the reactive gases}
- C30B 29/04: Diamond
- H01J 37/32192: {Microwave generated discharge (H01J37/32357, H01J37/32366, H01J37/32394, H01J37/32403 take precedence)}
- H01J 37/32449: {Gas control, e.g. control of the gas flow}
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}
- C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04)
- 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
- H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H)

## Abstract

A method of manufacturing synthetic CVD diamond material, the method comprising: providing a microwave plasma reactor comprising: a plasma chamber; one or more substrates disposed in the plasma chamber providing a growth surface area over which the synthetic CVD diamond material is to be deposited in use; a microwave coupling configuration for feeding microwaves from a microwave generator into the plasma chamber; and a gas flow system for feeding process gases into the plasma chamber and removing them therefrom, injecting process gases into the plasma chamber; feeding microwaves from the microwave generator into the plasma chamber through the microwave coupling configuration to form a plasma above the growth surface area; and growing synthetic CVD diamond material over the growth surface area, wherein the process gases comprise at least one dopant in gaseous form, selected from a one or more of boron, silicon, sulphur, phosphorous, lithium and beryllium at a concentration equal to or greater than 0.01 ppm and/or nitrogen at a concentration equal to or greater than 0.3 ppm, wherein the gas flow system includes a gas inlet comprising one or more gas inlet nozzles disposed opposite the growth surface area and configured to inject process gases towards the growth surface area, and wherein the process gases are injected towards the growth surface area at a total gas flow rate equal to or greater than 500 standard cm3 per minute and/or wherein the process gases are injected into the plasma chamber through the or each gas inlet nozzle with a Reynolds number a Reynolds number in a range 1 to 100.

## Claims

### Claim 1

A method of manufacturing synthetic CVD diamond material, the method comprising:
providing a microwave plasma reactor comprising:
a plasma chamber;
one or more substrates disposed in the plasma chamber providing a growth surface area over which the synthetic CVD diamond material is to be deposited in use; a microwave coupling configuration for feeding microwaves from a microwave generator into the plasma chamber; and
a gas flow system for feeding process gases into the plasma chamber and removing them therefrom,
injecting process gases into the plasma chamber;
feeding microwaves from the microwave generator into the plasma chamber through the microwave coupling configuration to form a plasma above the growth surface area or below the growth surface area if the microwave plasma reactor is in an inverted arrangement with process gases flowing in an upwards direction; and
growing synthetic CVD diamond material over the growth surface area, wherein the process gases comprise at least one dopant in gaseous form, selected from a one or more of boron, silicon, sulphur, phosphorous, lithium and beryllium, the or each dopant present at a concentration equal to or greater than 0.01 ppm, and/or nitrogen at a concentration equal to or greater than 0.3 ppm,
wherein the gas flow system includes a gas inlet comprising one or more gas inlet nozzles disposed opposite the growth surface area and configured to inject process gases towards the growth surface area, and
wherein the process gases are injected into the plasma chamber through the or each gas inlet nozzle with a Reynolds number in a range 1 to 100.

### Claim 2 (depends on 1)

A method according to claim 1, wherein the at least one dopant is added to one or more source process gases prior to injection into the plasma chamber.

### Claim 3 (depends on 1)

A method according to claim 1, wherein the at least one dopant comprises: one or more of boron, silicon, sulphur, phosphorous, lithium and beryllium and wherein the process gases comprise less than 0.3 ppm nitrogen; or nitrogen at a concentration of equal to or greater than 0.3 ppm and wherein the process gases comprise less than 0.01 ppm of the each of boron, silicon, sulphur, phosphorous, lithium and beryllium.

### Claim 4 (depends on 1)

A method according to claim 1, wherein the at least one dopant is provided in the process gases at a concentration equal to or greater than 0.05 ppm, 0.1 ppm, 0.3 ppm, 0.5 ppm, 0.7 ppm, 1 ppm, 3 ppm, 5 ppm, 10 ppm, 20 ppm, 50 ppm, 100 ppm, 200 ppm, 300 ppm, 500 ppm, 700 ppm, or 1000 ppm.

### Claim 5 (depends on 1)

A method according to claim 1, wherein the process gases comprise a ratio of dopant concentration/carbon concentration equal to or greater than 1×10−6, 10×10−6, 100×10−6, or 1000×10−6.

### Claim 6 (depends on 1)

A method according to claim 1, wherein the total gas flow rate fed through the gas inlet is equal to or greater than 750, 1000, 2000, 5000, 10000, 15000, 20000, 25000, 30000, 35000, or 40000 standard cm3 per minute.

### Claim 7 (depends on 1)

A method according to claim 1, wherein the total gas flow fed through the gas inlet is equal to or greater than 3, 10, 20, 50, 100, 200, 500, or 1000 standard cm3 per cm2 of the growth surface area and equal to or less than 50000, 20000, 10000, or 5000 standard cm3 per cm2 of the growth surface area.

### Claim 8 (depends on 1)

A method according to claim 1, wherein the or each gas inlet nozzle has an outlet diameter in the range 0.1 mm to 5 mm, 0.2 mm to 3.0 mm, 2.0 mm to 3 mm, 0.2 mm to 2 mm, 0.25 mm to 2 mm, or 0.25 mm to 1.5 mm.

### Claim 9 (depends on 1)

A method according to claim 1, wherein a minimum distance Dc between the gas inlet and the growth surface area is less than or equal to 6Rs, 4Rs, or 2Rs, where Rs is a radius of the growth surface area.

### Claim 10 (depends on 1)

A method according to claim 1, wherein the process gases are injected into the plasma chamber through the or each gas inlet nozzle with a Reynolds number equal to or less than 100, 80, 50, 40, or 35 and at least 1, 5, 10, 15, 20, or 25.

### Claim 11 (depends on 1)

A method according to claim 1, wherein an operating pressure within the plasma chamber is equal to or greater than: 100, 200, 220, 240, 260, 280, 300, 320, 340, 360, 380, or 400 Torr (13.3, 26.7, 29.3, 32.0, 34.7, 37.3, 40.0, 42.7, 45.3, 48.0, 50.7, 53.3 kPa) at a microwave frequency in a range 2300 to 2600 MHz; 120, 140 160, 180, 200, 220, 240, or 260 Torr (16.0, 18.7, 21.3, 24.0, 26.7, 29.3, 32.0, 34.7 kPa) at a microwave frequency in a range 800 to 1000 MHz; or 60, 70, 80, 100, 120, 140, or 150 Torr (8.0, 9.3, 10.7, 13.3, 16.0, 18.7, 20.0 kPa) at a microwave frequency in a range 400 to 500 MHz.

### Claim 12 (depends on 1)

A method according to claim 1, wherein at least 45%, 50%, 55%, 60%, 65%, or 70% of power fed into the plasma chamber is transmitted through a base of the plasma chamber disposed opposite to the gas inlet.

### Claim 13 (depends on 1)

A method according to claim 1, wherein a power density delivered to the growth surface area is equal to or greater than 0.05, 0.1, 0.5, 1, 1.5, 2.0, 2.5, 2.75, 3.0, 3.2, or 3.5 W/mm2 of the growth surface area.

### Claim 14 (depends on 1)

A method according to claim 1, wherein the gas inlet comprises an inlet nozzle array comprising a plurality of gas inlet nozzles disposed opposite the growth surface area and configured to inject process gases towards the growth surface area.

### Claim at position 15

15-54. (canceled)

### Claim 55 (depends on 1)

A method according to claim 1, wherein the process gases are injected towards the growth surface area at a total gas flow rate equal to or greater than 500 standard cm3 per minute.