Radiation window with coated silicon support structure

• US 7,709,820 B2
• Filed: 05/21/2008
• Issued: 05/04/2010
• Est. Priority Date: 06/01/2007
• Status: Expired due to Fees

• Current Assignee: Moxtek (Polatechno Co.,Ltd.)
• Original Assignee: Moxtek (Polatechno Co.,Ltd.)
• Inventors: Perkins, Raymond, Lines, Mike, Decker, Keith W., Xu, Degao
• Primary Examiner(s): NGUYEN, KIET TUAN
• Application Number:
  US12/124,917
• Publication Number:
  US 20090173897A1
• Time in Patent Office: 713 Days
• Field of Search: 250/505.1, 250/310
• US Class Current: 250/505.1
• CPC Class Codes: G21K 1/00 Arrangements for handling particles or ionising radiation, e.g. focusing or moderating production or acceleration of neutrons, electrically-charged particles, neutral molecular beams or neutral atomic beams H05H3/00 - H05H15/00
• CPC Class Codes: H01J 2237/164 Particle-permeable windows
• CPC Class Codes: H01J 2237/2445 Photon detectors for X-rays, light, e.g. photomultipliers
• CPC Class Codes: H01J 2237/28 Scanning microscopes
• CPC Class Codes: H01J 37/244 Detectors; Associated components or circuits therefor
• CPC Class Codes: H01J 5/18 Windows permeable to X-rays, gamma-rays, or particles

Abstract

A window for a radiation detection system includes a frame with an aperture therein configured to receive radiation therethrough. A plurality of silicon ribs span the aperture and are carried by the frame. A coating substantially envelopes each of the plurality of silicon ribs. A thin film covers the aperture and is carried by the plurality of silicon ribs and is configured to pass radiation therethrough.

Claims

1. A window for a radiation detection system, the window comprising:

a) a frame with an aperture therein configured to receive radiation therethrough;

b) a plurality of silicon ribs spanning the aperture and carried by the frame;

c) a coating substantially enveloping each of the plurality of silicon ribs; and

d) a thin film covering the aperture and carried by the plurality of silicon ribs and configured to pass radiation therethrough.

2. A window as in claim 1, wherein a substantially coated silicon rib is stronger than an uncoated silicon rib.

3. A window as in claim 1, wherein the plurality of silicon ribs with a coating substantially enveloping each rib has an equal strength or a greater strength, and ribs with less cross section or fewer ribs, than a plurality of un-coated ribs with a greater number of ribs or wider cross section.

4. A window as in claim 1, wherein the coating surrounds a cross-sectional perimeter of the plurality of silicon ribs.

5. A window as in claim 1, wherein the plurality of silicon ribs has a height less than 100 μ

m.

6. A window as in claim 1, wherein the coating is low-atomic mass less than 28 grams/mol.

7. A window as in claim 1, wherein the coating is a low atomic mass element or compound selected from the group consisting of:

Beryllium, Boron, Carbon, Magnesium, Aluminum, Diamond, Silicon Carbide, Boron Carbide, Boron Nitride, Silicon Nitride, and Beryllium Oxide.

8. A window as in claim 1, wherein the coating is at least partially diffused into each silicon rib.

9. A window as in claim 1, wherein each silicon rib is less than 100 μ

m wide.

10. A window as in claim 1, wherein each silicon rib is oriented parallel with respect to each other.

11. A window as in claim 1, wherein the plurality of upstanding silicon ribs includes a first set of parallel silicon ribs oriented non-parallel with respect to and intersecting a second set of parallel silicon ribs.

12. A window as in claim 1, wherein the film is polymeric.

13. A window as in claim 1, further comprising a gas barrier film layer disposed over the film.

14. A radiation detection system comprising:

a) a window configured to pass radiation therethrough, the window comprising;

i) a frame with an aperture therein configured to receive radiation therethrough;

ii) a plurality of silicon ribs spanning the aperture and carried by the frame;

iii) a coating substantially enveloping each of the plurality of silicon ribs; and

iv) a thin film covering the aperture and carried by the plurality of silicon ribs and configured to pass radiation therethrough; and

b) a sensor disposed behind the window configured to detect radiation passing through the window.

15. A method of making a window for a radiation detection system, the method comprising:

a) forming a frame with an aperture and a plurality of silicon ribs spanning the aperture;

b) coating the plurality of silicon ribs to form a plurality of coated silicon ribs;

c) forming a thin film of material; and

d) covering the aperture with the thin film wherein the thin film is secured on tops of the plurality of coated silicon ribs.

16. A method as in claim 15 wherein coating further comprises e-beam metal evaporation of a metal comprising one or more metal selected from aluminum, magnesium, or beryllium.

17. A method as in claim 15 wherein coating further comprises growing a silicon dioxide coating on the plurality of silicon ribs.

18. A method as in claim 15 wherein coating further comprises:

a) removing a native oxide coating on the plurality of silicon ribs; and

b) immersing the plurality of silicon ribs into a furnace purged with dry nitrogen or ammonia to form a silicon nitride coating on the plurality of silicon ribs.

19. A method as in claim 15 wherein coating further comprises:

a) removing a native oxide coating on the plurality of silicon ribs; and

b) immersing the plurality of silicon ribs into a furnace with a diborane gas, argon gas, and RF plasma to form a boron hydride coating on the plurality of silicon ribs.