Method of fabricating a diamond membrane

Patent metadata

Field	Value
Publication number	US-10119201-B2
Application number	US-201515519220-A
Country	US
Kind code	B2
Filing date	Oct 15, 2015
Priority date	Oct 15, 2014
Publication date	Nov 6, 2018
Grant date	Nov 6, 2018

Abstract

The present disclosure provides a method of fabricating a diamond membrane. The method comprises providing a substrate and a support structure. The substrate comprises a diamond material having a first surface and the substrate further comprises a sub-surface layer that is positioned below the first surface and has a crystallographic structure that is different to that of the diamond material. The sub-surface layer is positioned to divide the diamond material into first and second regions wherein the first region is positioned between the first surface and the sub-surface layer. The support structure also comprises a diamond material and is connected to, and covers a portion of, the first surface of the substrate. The method further comprises selectively removing the second region of the diamond material from the substrate by etching away at least a portion of the sub-surface layer of the substrate.

First claim

The claims defining the invention are as follows:

1. A method of fabricating a diamond membrane, the method comprising:
providing a substrate and a support structure, the substrate comprising a diamond material and having a first surface, the substrate further comprising a sub-surface layer that is positioned below the first surface of the substrate and has a crystallographic structure that is different to that of the diamond material, the sub-surface layer of the substrate being positioned to divide the diamond material into first and second regions wherein the first region is positioned between the first surface of the substrate and the sub-surface layer of the substrate, the support structure also comprising a diamond material and being connected to, and covering a portion of, the first surface of the substrate, the diamond material of the support structure comprising apertures;
coupling the diamond material of the support structure to the first surface of the substrate in a manner such that portions of the first surface of the substrate are exposed within the apertures of the diamond material of the support structure;
growing further diamond material on the first surface of the substrate at locations within the apertures of the diamond material of the support structure or at locations around the support structure to fuse the support structure to the substrate; and
selectively removing the second region of the diamond material from the substrate by etching away at least a portion of the sub-surface layer of the substrate whereby a diamond membrane is formed and the support structure is connected to, and supports, the formed diamond membrane.

2. The method of claim 1 wherein providing the substrate comprises growing a layer of substantially single-crystalline diamond material on the diamond material of the substrate such that a surface of the substantially single-crystalline diamond layer forms the first surface of the substrate.

3. The method of claim 1 wherein the diamond material of the support structure comprises a sheet of the diamond material comprising the apertures, wherein the apertures are formed by laser milling.

4. The method of claim 1 comprising depositing a metallic material on the first surface of the substrate to form a metallic mask having apertures.

5. The method of claim 4 comprising growing further diamond material on the first surface of the substrate and within apertures of the metallic mask to form the support structure.

6. The method of claim 4 being conducted such that polycrystalline diamond material forms on surface portions of the metallic mask.

7. The method of claim 1 wherein the first and/or the second region of the substrate is substantially single-crystalline.

8. The method of claim 1 comprising removing at least a portion of the first region of the diamond material of the substrate after removal of the second region.

9. The method of claim 1 wherein the diamond material of the support structure has a substantially single-crystalline structure.

10. The method of claim 1 wherein the support structure is arranged relative to the substrate such that portions of a fabricated membrane of the diamond material that are not covered by the support structure form windows.

11. The method of claim 1 wherein the step of providing the substrate comprises:
providing the diamond material of the substrate; and
forming the sub-surface layer by imposing a structural transformation on the crystallographic structure of the diamond material of the substrate.

12. A method of fabricating a diamond membrane, the method comprising:
providing a substrate and a support structure, the substrate comprising a diamond material and having a first surface, the substrate further comprising a sub-surface layer that is positioned below the first surface of the substrate and has a crystallographic structure that is different to that of the diamond material, the sub-surface layer of the substrate being positioned to divide the diamond material into first and second regions wherein the first region is positioned between the first surface of the substrate and the sub-surface layer of the substrate, the support structure also comprising a diamond material and being connected to, and covering a portion of, the first surface of the substrate; and
selectively removing the second region of the diamond material from the substrate by etching away at least a portion of the sub-surface layer of the substrate, whereby a diamond membrane is formed and the support structure is connected to, and supports, the formed diamond membrane;
wherein providing the substrate and the support structure comprises growing the support structure on the substrate, wherein growing the support structure on the substrate comprises placing a mask having a plurality of apertures on the first surface of the substrate such that portions of the first surface of the substrate are exposed within the apertures.

13. The method of claim 12 comprising growing further diamond material on the first surface of the substrate and within the plurality of apertures of the mask to form the support structure.

14. The method of claim 13 wherein the mask comprises diamond material that is polycrystalline.

Assignees

• Univ Melbourne

Inventors

• Piracha Afaq Habib
• Prawer Steven
• Ganesan Kumaravelu
• Tomljenovic-Hanic Snjezana
• Lau Desmond

Classifications

• B23K26/0006

  taking account of the properties of the material involved (B23K26/32, B23K26/40 take precedence) · CPC title

• C23C16/4408

  by purging residual gases from the reaction chamber or gas lines · CPC title

• C30B33/12

  in gas atmosphere or plasma · CPC title

• C23C16/274

  using microwave discharges · CPC title

• B23K26/362

  Laser etching · CPC title