Synthetic CVD diamond

Patent metadata

Field	Value
Publication number	US-10480097-B2
Application number	US-201916352934-A
Country	US
Kind code	B2
Filing date	Mar 14, 2019
Priority date	Dec 22, 2009
Publication date	Nov 19, 2019
Grant date	Nov 19, 2019

Abstract

The present disclosure relates to methods for synthesizing synthetic CVD diamond material and high quality synthetic CVD diamond materials.

First claim

The invention claimed is:

1. A chemical vapour deposition (CVD) method for synthesizing diamond material on a substrate in a synthesis environment, said method comprising:
providing the substrate;
providing a source gas;
dissociating the source gas; and
allowing homoepitaxial diamond synthesis on the substrate;
wherein the synthesis environment comprises nitrogen at an atomic concentration of from about 0.4 ppm to about 50 ppm; and
and wherein the source gas comprises:
a) an atomic fraction of hydrogen, H f , from about 0.40 to about 0.75;
b) an atomic fraction of carbon, C f , from about 0.15 to about 0.30;

c) an atomic fraction of oxygen, O f , from about 0.13 to about 0.40;
wherein H f C f O f =1;
wherein the ratio of atomic fraction of carbon to the atomic fraction of oxygen, C f :O f , satisfies the ratio of about 0.45:1<C f :O f <about 1.25:1;
wherein the source gas comprises hydrogen atoms added as hydrogen molecules, H 2 , at an atomic fraction of the total number of hydrogen, oxygen and carbon atoms present of between 0.05 and 0.40; and
wherein the atomic fractions H f , C f and O f are fractions of the total number of hydrogen, oxygen and carbon atoms present in the source gas.

2. The method according to claim 1 , wherein the process is carried out at a pressure greater than P lower Torr, where P lower =P arc −Y and P arc =170(H f +0.25)+X, where Y=50 Torr and X is from about 20 to about −50 and P arc is the pressure of the onset of unipolar arcing in the process.

3. The method according to claim 1 , wherein the source gas is dissociated by microwaves.

4. The method according to claim 3 , wherein the frequency of the microwaves is from about 800 MHz to about 1000 MHz.

5. The method according to claim 1 , wherein the substrate is maintained at a temperature of from about 750° C. to about 1000° C.

Assignees

• Element Six Tech Ltd

Inventors

• Twitchen Daniel James
• Bennett Andrew Michael
• Khan Rizwan Uddin Ahmad
• Martineau Philip Maurice

Classifications

• C01B32/26

  Preparation (by using ultra-high pressure B01J3/06; by crystal growth C30B29/04) · CPC title

• C30B25/20

  the substrate being of the same materials as the epitaxial layer · CPC title

• C30B25/165

  the flow of the reactive gases · CPC title

• C30B25/186

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

• C30B29/04 Primary

  Diamond · CPC title