Single crystal synthetic diamond material

Patent metadata

Field	Value
Publication number	US-12037702-B2
Application number	US-202318488602-A
Country	US
Kind code	B2
Filing date	Oct 17, 2023
Priority date	Mar 29, 2019
Publication date	Jul 16, 2024
Grant date	Jul 16, 2024

Abstract

Single crystal CVD diamond material comprising a total nitrogen concentration of at least 5 ppm and a neutral single substitutional nitrogen, N s 0 , to total single substitutional nitrogen, N s , ratio of at least 0.7. Such a diamond is observed to have a relatively low amount of brown colouration despite the relatively high concentration of nitrogen. A method of making the single crystal diamond is also disclosed, the method including growing the CVD diamond in process gases comprising 60 to 200 ppm nitrogen, in addition to a carbon-containing gas, and hydrogen, wherein the ratio of carbon atoms in the carbon-containing gas to hydrogen atoms in the hydrogen gas is 0.5 to 1.5%.

First claim

What is claimed is:

1. A method of making single crystal CVD diamond comprising a total nitrogen concentration of at least 5 ppm and a neutral single substitutional nitrogen, N s 0 , to total single substitutional nitrogen, N s , ratio of at least 0.7, the method comprising:
locating a single crystal diamond substrate over a substrate holder within a chemical vapour deposition reactor;
feeding process gases into the reactor, the process gases comprising 60 to 200 ppm nitrogen, a carbon-containing gas and hydrogen, wherein a ratio of carbon atoms in the carbon-containing gas to hydrogen atoms in the hydrogen gas is 0.5 to 1.5%; and
growing single crystal CVD diamond material on a surface of the single crystal diamond substrate.

2. The method according to claim 1 , wherein the ratio of carbon atoms in the carbon-containing gas to hydrogen atoms in the hydrogen gas is no more than 1.0%.

3. The method according to claim 1 , the method further comprising locating a plurality of single crystal diamond substrates over the substrate holder.

4. The method according claim 1 , further comprising irradiating and annealing the diamond material to increase a number of NV − defects in the diamond material.

5. The method according claim 1 , wherein the single crystal diamond substrate has a total nitrogen concentration of less than 5 ppm.

6. The method according to claim 1 , further comprising applying a mask to the diamond substrate prior to growing the single crystal CVD diamond material on the surface of the single crystal diamond substrate.

7. The method according to claim 1 , wherein the carbon in the carbon-containing gas comprises any of at least 99 percent 12 C; at least 99.9 percent 12 C; and at least 99.99 percent 12 C.

8. The method according to claim 1 , wherein the single crystal CVD diamond material is grown to a thickness selected from any of 100 nm to 4 mm, 200 nm to 1 mm, or 500 nm to 50 μm.

Assignees

• Element Six Tech Ltd

Inventors

• Edmonds Andrew Mark
• Markham Matthew Lee
• Colard Pierre-Olivier Francois Marc

Classifications

• C30B33/00

  After-treatment of single crystals or homogeneous polycrystalline material with defined structure (C30B31/00 takes precedence) · CPC title

• C30B29/68

  Crystals with laminate structure, e.g. "superlattices" · CPC title

• C30B25/205

  the substrate being of insulating material · CPC title

• C30B25/186

  being specially pre-treated by, e.g. chemical or physical means · CPC title

• C23C16/56

  After-treatment · CPC title