Methods of producing optically-finished thin diamond substrates or windows of high aspect ratio

Patent metadata

Field	Value
Publication number	US-11618945-B2
Application number	US-201916663423-A
Country	US
Kind code	B2
Filing date	Oct 25, 2019
Priority date	Apr 16, 2015
Publication date	Apr 4, 2023
Grant date	Apr 4, 2023

Abstract

In a method of forming a diamond film, substrate, or window, a substrate is provided and the diamond film, substrate, or window is CVD grown on a surface of the substrate. The grown diamond film, substrate, or window has a thickness between 150-999 microns and an aspect ratio≥100, wherein the aspect ratio is a ratio of a largest dimension of the diamond film, substrate or window divided by a thickness of the diamond film. The substrate can optionally be removed or separated from the grown diamond film, substrate, or window.

First claim

The invention claimed is:

1. A method of forming a free-standing diamond film comprising:
(a) CVD growing on a surface of a substrate a diamond film having an aspect ratio ≥100 and a thickness between 150-999 microns, wherein the grown diamond film has a nucleation side surface and a growth side surface opposite the nucleation side surface and the nucleation side surface of the grown diamond film has an optical finish having a surface roughness (Ra)≤50 nm;
(b) removing the substrate from the grown diamond film; and
(c) polishing the surface of the substrate to an optical finish having a surface roughness (Ra)≤20 nm wherein the polishing is completed prior to the CVD growing step,
wherein the method further comprises the step of polishing the growth side surface to an optical finish having a surface roughness (Ra)≤50 nm and the polishing the growth side surface step occurs after the growing step and prior to the removing step.

2. The method of claim 1 , wherein the substrate has a thickness ≥2 mm.

3. The method of claim 1 , wherein, prior to step (a), the surface of the substrate is seeded with diamond particles.

4. The method of claim 3 , wherein the substrate is seeded with diamond particles via at least one of the following processes: (1) ultrasonic treatment of the substrate in a ultrasonic bath comprised of a submicron or micron-sized diamond powder in a liquid suspension solution; and (2) ultrasonic treatment of the substrate in a ultrasonic bath comprised of nano-crystal diamond powder having an average particle size <100 nm in a liquid suspension solution.

5. The method of claim 4 , wherein the liquid suspension solution comprises one or more of the following: water, alcohol, hydrocarbon, and organic solvent.

6. The method of claim 5 , wherein the substrate is seeded with diamond particles via a least one of the following processes: (1) ultrasonic treatment of the substrate in a bath of aqueous diamond slurries or organic diamond slurries, or (2) rubbing the substrate with diamond powders.

7. The method of claim 1 , wherein the largest dimension of the substrate is a diameter of the substrate.

8. The method of claim 1 , wherein the substrate has a thickness ≥8 mm.

9. The method of claim 1 , further including, prior to step (a), polishing the surface of the substrate to an optical finish having a surface roughness (Ra)≤2 nm.

10. The method of claim 1 , wherein polishing the growth side surface includes polishing the growth side to an optical finish having a surface roughness (Ra)≤30 nm.

11. The method of claim 1 , wherein polishing the growth side surface includes polishing the growth side to an optical finish having a surface roughness (Ra)≤20 nm.

12. The method of claim 1 , wherein polishing the growth side surface includes polishing the growth side to an optical finish having a surface roughness (Ra)≤15 nm.

13. The method of claim 1 , wherein polishing the growth side surface includes polishing the growth side to an optical finish having a surface roughness (Ra)≤10 nm.

14. The method of claim 1 , wherein the diamond film has a diamond nucleation density ≥1.0×10 5 /cm 2 .

15. The method of claim 1 , wherein the surface of the substrate has a shape of at least one of a cone, a pyramid, an asphere, a parabola, a hyperbola, and a non-planar surface.

16. The method of claim 1 , wherein the surface of the substrate is planar.

Assignees

• Ii Vi Delaware Inc

Inventors

• Xu Wen-Qing
• Anderson Thomas E
• Barbarossa Giovanni
• Eissler Elgin E
• Liu Chao
• Tanner Charles D

Classifications

• Y10T428/30

  Self-sustaining carbon mass or layer with impregnant or other layer · CPC title

• C23C16/56

  After-treatment · CPC title

• C23C16/511

  using microwave discharges · CPC title

• C23C16/01

  on temporary substrates, e.g. substrates subsequently removed by etching · CPC title

• C23C16/02

  Pretreatment of the material to be coated (C23C16/04 takes precedence) · CPC title