Method of fabricating a neutron detector such as a microstructured semiconductor neutron detector

• US 8,778,715 B2
• Filed: 06/24/2013
• Issued: 07/15/2014
• Est. Priority Date: 06/25/2012
• Status: Active Grant

• Current Assignee: Radiation Detection Technologies, Inc.
• Original Assignee: Radiation Detection Technologies, Inc.
• Inventors: Bellinger, Steven L., Fronk, Ryan G., McGregor, Douglas S.
• Primary Examiner(s): Lee, Cheung
• Application Number:
  US13/924,839
• Publication Number:
  US 20130344636A1
• Time in Patent Office: 386 Days
• Field of Search: 438/56, 438/361, 257/E21.483
• US Class Current: 438/56
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: G01T 3/00 Measuring neutron radiation G01T5/00 takes precedence
• CPC Class Codes: H01L 31/115 Devices sensitive to very short wavelength, e.g. X-rays, gamma-rays or corpuscular radiation
• CPC Class Codes: H01L 31/18 Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof
• CPC Class Codes: H01L 31/1804 comprising only elements of Group IV of the Periodic Table
• CPC Class Codes: Y02E 10/547 Monocrystalline silicon PV cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10S 977/773 Nanoparticle, i.e. structure having three dimensions of 100 nm or less
• CPC Class Codes: Y10S 977/89 Deposition of materials, e.g. coating, cvd, or ald
• CPC Class Codes: Y10S 977/953 Detector using nanostructure

Abstract

A method of making a neutron detector such as a microstructured semiconductor neutron detector is provided. The method includes the step of providing a particle-detecting substrate having a surface and a plurality of cavities extending into the substrate from the surface. The method also includes filling the plurality of cavities with a neutron-responsive material. The step of filling including the step of centrifuging nanoparticles of the neutron-responsive material with the substrate for a time and a rotational velocity sufficient to backfill the cavities with the nanoparticles. The material is responsive to neutrons absorbed, thereby, for releasing ionizing radiation reaction products.

Claims

1. A method of making a neutron detector, the method comprising:

providing a particle-detecting substrate having a surface and a plurality of cavities extending into the substrate from the surface; and

filling the plurality of cavities with a neutron-responsive material, the step of filling including the step of centrifuging nanoparticles of the neutron-responsive material with the substrate for a time and at a rotational velocity sufficient to backfill the cavities with the nanoparticles, the material being responsive to neutrons absorbed thereby for releasing ionizing radiation reaction products.

2. The method of claim 1, wherein the step of providing includes a step of forming a dielectric layer and a patterned hard mask layer sequentially on the substrate.

3. The method of claim 2, wherein the step of providing includes a step of removing a portion of the dielectric layer with an etch to form an opening to expose the substrate.

4. The method of claim 3, wherein the step of providing includes a step of submerging the substrate into a directionally orientated, semiconductor etching solution to produce the cavities.

5. The method as claimed in claim 4, wherein the step of providing includes a step of introducing dopant impurities into the cavities to produce a rectifying junction in the cavities.

6. The method as claimed in claim 5, wherein the junction is a pn junction.

7. The method as claimed in claim 3, wherein the step of providing includes a step of introducing metallic materials or metallic alloys into the cavities to produce a Schottky barrier rectifying junction in the cavities.

8. The method as claimed in claim 3, wherein the step of providing includes a step of introducing dopant impurities into the cavities to produce an ohmic contact in the cavities.

9. The method as claimed in claim 1, wherein the substrate is a semiconductor substrate.

10. The method as claimed in claim 9, wherein the detector is a microstructured semiconductor neutron detector.

11. The method as claimed in claim 1, wherein the nanoparticles are suspended in a colloidal solution during the step of centrifuging.

12. The method as claimed in claim 1, wherein the cavities are deep anisotropic cavities.

13. The method of making a neutron detector, the method including providing a particle-detecting substrate having a surface and a plurality of cavities extending into the substrate from the surface, and filling the plurality of cavities with a neutron-responsive material, the material being responsive to neutrons absorbed thereby for releasing ionizing radiation reaction products, an improvement comprising:

the step of filling includes the step of centrifuging nanoparticles of the neutron-responsive material with the substrate for a time and at a rotational velocity sufficient to backfill the cavities with the nanoparticles.

14. The method of claim 13, wherein the step of providing includes a step of forming a dielectric layer and a patterned hard mask layer sequentially on the substrate.

15. The method of claim 14, wherein the step of providing includes a step of removing a portion of the dielectric layer with an etch to form an opening to expose the substrate.

16. The method of claim 15, wherein the step of providing includes a step of submerging the substrate into a directionally orientated, semiconductor etching solution to produce the cavities.

17. The method as claimed in claim 16, wherein the step of providing includes a step of introducing dopant impurities into the cavities to produce a rectifying junction in the cavities.

18. The method as claimed in claim 17, wherein the junction is a pn junction.

19. The method as claimed in claim 16, wherein the step of providing includes a step of introducing metallic materials or metallic alloys into the cavities to produce a Schottky barrier rectifying junction in the cavities.

20. The method as claimed in claim 16, wherein the step of providing includes a step of introducing dopant impurities into the cavities to produce an ohmic contact in the cavities.

21. The method as claimed in claim 13, wherein the substrate is a semiconductor substrate.

22. The method as claimed in claim 21, wherein the detector is a microstructured semiconductor neutron detector.

23. The method as claimed in claim 13, wherein the nanoparticles are suspended in a colloidal solution during the step of centrifuging.

24. The method as claimed in claim 13, wherein the cavities are deep anisotropic cavities.