Chemical vapor deposition growth of hexagonal boron nitride films and nanostructures

Patent metadata

Field	Value
Publication number	US-12571128-B2
Application number	US-202318369370-A
Country	US
Kind code	B2
Filing date	Sep 18, 2023
Priority date	Sep 18, 2023
Publication date	Mar 10, 2026
Grant date	Mar 10, 2026

Abstract

A scalable method of synthesizing hexagonal boron nitride (hBN) films and nanotubes by chemical vapor deposition (CVD) is provided. The method includes atmospheric pressure CVD of hBN on metallic growth substrates using solid boron sources and molecular nitrogen. The solid boron source can be in the form of powder, fragments, or platelets and placed upstream, on top, or below the growth substrate. The growth substrate can include Fe, Ni, Cr, Cu, and their alloys including various steels. The growth atmosphere includes nitrogen compounds, inert gases and hydrogen. The reaction can occur within a reaction vessel heated to 800° C.-1200° C. in less than 120 minutes with sequential cooling at a controlled rate. In laboratory testing, the hBN film exhibited improved protection against harsh corrosion over long periods and resistance to high-temperature oxidation in air.

First claim

The invention claimed is:

1. A method of synthesizing hexagonal boron nitride, the method comprising:
positioning a solid boron-containing precursor and a continuous growth substrate within a chemical vapor deposition chamber, wherein the solid boron-containing precursor includes boron powders, boron fragments, or boron platelets and does not directly contact the continuous growth substrate, wherein the continuous growth substrate includes nickel, iron, copper, chromium, or alloys thereof, and wherein the continuous growth substrate is unwound from a supply reel;
heating an interior of the chemical vapor deposition chamber to between 800° C. and 1200° C., inclusive;
flowing a nitrogen-containing reaction gas mixture into the chemical vapor deposition chamber, the reaction gas mixture including a nitrogen compound and hydrogen gas, wherein the reaction gas mixture is pressurized between 10 mTorr and 800 Torr, inclusive, wherein the reaction gas mixture includes a ratio of a partial pressure of nitrogen to a partial pressure of hydrogen of greater than 30, and wherein the continuous growth substrate reacts with boron released from the solid boron-containing precursor and the nitrogen compound to form a single-layer or multi-layer hexagonal boron nitride film on the continuous growth substrate; and
taking up the continuous growth substrate onto a take-up reel after formation of the hexagonal boron nitride film on the continuous growth substrate.

2. The method of claim 1 , wherein the nitrogen compound comprises molecular nitrogen (N 2 ).

3. The method of claim 1 , wherein the nitrogen compound comprises ammonia (NH 3 ).

4. The method of claim 1 , wherein the reaction gas mixture includes a concentration of between 0.01% and 25% of hydrogen gas (H 2 ).

5. The method of claim 1 , wherein the solid boron-containing precursor is supported above the continuous growth substrate.

6. The method of claim 1 , wherein the solid boron-containing precursor is supported below the continuous growth substrate.

7. The method of claim 1 , wherein the solid boron-containing precursor is supported laterally adjacent to the continuous growth substrate.

8. A method of synthesizing hexagonal boron nitride, the method comprising:
positioning a solid boron-containing precursor and a growth substrate within a chemical vapor deposition chamber, wherein the solid boron-containing precursor includes boron powders, boron fragments, or boron platelets and does not directly contact the growth substrate, and wherein the growth substrate includes nickel, iron, copper, chromium, or alloys thereof;
heating an interior of the chemical vapor deposition chamber to between 800° C. and 1200° C., inclusive; and
flowing a nitrogen-containing reaction gas mixture into the chemical vapor deposition chamber, the reaction gas mixture including a nitrogen compound and hydrogen gas;
wherein the reaction gas mixture is pressurized between 10 mTorr and 800 Torr, inclusive, wherein the growth substrate reacts with boron released from the solid boron-containing precursor and the nitrogen compound to form a single-layer or multi-layer hexagonal boron nitride film, and wherein the growth substrate comprises a film having a thickness of between 0.1 μm and 5.0 μm, inclusive.

9. A method of synthesizing hexagonal boron nitride, the method comprising:
positioning a solid boron-containing precursor and a growth substrate within a chemical vapor deposition chamber, wherein the solid boron-containing precursor includes boron powders, boron fragments, or boron platelets and does not directly contact the growth substrate, and wherein the growth substrate includes nickel, iron, copper, chromium, or alloys thereof;
heating an interior of the chemical vapor deposition chamber to between 800° C. and 1200° C., inclusive; and
flowing a nitrogen-containing reaction gas mixture into the chemical vapor deposition chamber, the reaction gas mixture including a nitrogen compound and hydrogen gas;
wherein the reaction gas mixture is pressurized between 10 mTorr and 800 Torr, inclusive, wherein the growth substrate reacts with boron released from the solid boron-containing precursor and the nitrogen compound to form a single-layer or multi-layer hexagonal boron nitride film, and wherein the growth substrate comprises a foil having a thickness of between 5.0 μm and 150 μm, inclusive.

10. A method of synthesizing hexagonal boron nitride, the method comprising:
positioning a solid boron-containing precursor and a growth substrate within a chemical vapor deposition chamber, wherein the solid boron-containing precursor includes boron powders, boron fragments, or boron platelets and does not directly contact the growth substrate, and wherein the growth substrate includes nickel, iron, copper, chromium, or alloys thereof;
heating an interior of the chemical vapor deposition chamber to between 800° C. and 1200° C., inclusive; and
flowing a nitrogen-containing reaction gas mixture into the chemical vapor deposition chamber, the reaction gas mixture including a nitrogen compound and hydrogen gas;
wherein the reaction gas mixture is pressurized between 10 mTorr and 800 Torr, inclusive, wherein the growth substrate reacts with boron released from the solid boron-containing precursor and the nitrogen compound to form a single-layer or multi-layer hexagonal boron nitride film, and wherein the growth substrate comprises a sheet having a thickness of between 0.15 mm and 5 mm, inclusive.

11. A method of synthesizing hexagonal boron nitride, the method comprising:
positioning a solid boron-containing precursor and a growth substrate within a chemical vapor deposition chamber, wherein the solid boron-containing precursor includes boron powders, boron fragments, or boron platelets and does not directly contact the growth substrate, and wherein the growth substrate includes nickel, iron, copper, chromium, or alloys thereof;
heating an interior of the chemical vapor deposition chamber to between 800° C. and 1200° C., inclusive; and
flowing a nitrogen-containing reaction gas mixture into the chemical vapor deposition chamber, the reaction gas mixture including a nitrogen compound and hydrogen gas;
wherein the reaction gas mixture is pressurized between 10 mTorr and 800 Torr, inclusive, wherein the growth substrate reacts with boron released from the solid boron-containing precursor and the nitrogen compound to form a single-layer or multi-layer hexagonal boron nitride film, and wherein the growth substrate comprises a plate having a thickness of between 5 mm and 100 mm, inclusive.

12. A method of synthesizing hexagonal boron nitride, the method comprising:
positioning a solid boron-containing precursor and a growth substrate within a chemical vapor deposition chamber, wherein the solid boron-containing precursor includes boron powders, boron fragments, or boron platelets and does not directly contact the growth substrate, and wherein the growth substrate includes nickel, iron, copper, chromium, or alloys thereof;
heating an interior of the chemical vapor deposition chamber to between 800° C. and 1200° C., inclusive; and
flowing a nitrogen-containing reaction gas mixture into the chemical vapor deposition chamber, the reaction gas mixture including a nitrogen compound and hydrogen gas;
wherein the reaction gas mixture is pressurized between 10 mTorr and 800 Torr, inclusive, wherein the growth substrate reacts with boron released from the solid boron-containing precursor and the nitrogen compound to form a single-layer or multi-layer hexagonal boron nitride film, and wherein the growth substrate comprises includes a three-dimensional geometry including at least one

Assignees

• Ut Battelle Llc

Inventors

• Ivanov Ilia N
• Vlassiouk Ivan V
• Briggs Dayrl P

Classifications

• C30B25/165

  the flow of the reactive gases · CPC title

• C30B29/64

  Flat crystals, e.g. plates, strips or discs · CPC title

• C30B28/14

  by chemical reaction of reactive gases · CPC title

• C30B29/602

  Nanotubes · CPC title

• C30B25/12

  Substrate holders or susceptors · CPC title