Gratings for X-ray imaging, consisting of at least two materials

Patent metadata

Field	Value
Publication number	US-9230703-B2
Application number	US-201113703826-A
Country	US
Kind code	B2
Filing date	May 16, 2011
Priority date	Jun 17, 2010
Publication date	Jan 5, 2016
Grant date	Jan 5, 2016

Abstract

Gratings for analyzing the interference image in interferometers for phase contrast X-ray tomography, comprising a carrier and grating webs produced from at least two different materials, method for producing the same and use thereof.

First claim

What is claimed is:

1. An absorption grating, wherein the grating is suitable for analyzing an interference image in an interferometer for x-ray imaging by a phase contrast method and/or dark field imaging and comprises a carrier and at least two materials which absorb x-rays, the at least two materials comprising (a) gold or lead and (b) a material comprising an element with an atomic number lower than that of gold and down to that of barium, and wherein the grating has a layer structure selected from
(i) carrier/ML1/ML2,
(ii) carrier/ML1/ML2/ML3,
(iii) carrier/ML1/ML2/ML3/ML4,
(iv) carrier/ML1/ML2/ML3/ML4/ML5,
(v) ML1/carrier/ML2,
(vi) ML1/ML2/carrier/ML3,
(vii) ML1/ML2/carrier/ML3/ML4,
(viii) ML1/ML2/ML3/carrier/ML4,
(ix) ML1/ML2/ML3/carrier/ML4/ML5,

wherein ML stands for material layer or metal layer.

2. The grating of claim 1 , wherein the at least two materials are both metals.

3. The grating of claim 1 , wherein the grating has a layer structure (i).

4. The grating of claim 1 , wherein the grating has a layer structure (v).

5. The grating of claim 1 , wherein the grating consists of a carrier and exactly two materials.

6. The grating of claim 5 , wherein the two materials are gold and tungsten.

7. The grating of claim 6 , wherein a ratio of a layer thickness of W to a layer thickness of Au is from 1:2 to 1:6.

8. The grating of claim 7 , wherein the layer structure is carrier/Au/W or W/carrier/Au.

9. The grating of claim 7 , wherein the layer structure is carrier/W/Au.

10. The grating of claim 1 , wherein the at least two materials comprise a combination selected from Pb/Pt, Pb/W, Pb/Ta, Au/Ta, Au/Ba, Au/BaF 2 , Au/Gd 2 O 2 S.

11. The grating of claim 1 , wherein the carrier is selected from one or more of silicon, silicon compounds, polymers, and materials having a low atomic number.

12. A method for producing the grating of claim 1 , wherein the method comprises:
(a1) working a grating structure into a carrier wafer,
(b1) filling the grating structure with a first material,
(c1) removing first material deposited on a surface and thinning the wafer back on a rear side,
(d1.1) applying onto a front side (composite structure first material/wafer) a metallic layer, or
(d1.2) applying onto a rear side (composite structure first material/wafer) a metallic layer, which layer later serves as an electroplating start layer,
(e1) applying a negative resist on the metallic layer and patterning the resist with X-ray radiation in accordance with a LIGA method
(f1.1) from a front side, or
(f1.2) from a rear side,

(g1) filling freely developed trenches with a second material.

13. A method for producing the grating of claim 1 , wherein the method comprises:
(a2) working a grating structure into a carrier wafer,
(b2) filling the grating structure with a first material,
(c2) removing first material deposited on a surface and thinning the wafer back on a rear side,
(d2.1) applying onto a front side (composite structure first material/wafer) a metallic layer, or
(d2.2) applying onto a rear side (composite structure first material/wafer) a metallic layer, which layer later serves as an electroplating start layer,
(e2) applying a positive resist on the metallic layer, and
(f2) patterning the positive resist with X-ray radiation from the front side or rear side via an aligned mask in accordance with a LIGA method.

14. A method for producing the grating of claim 1 , wherein the method comprises:
(a3) working a grating structure into a carrier wafer,
(b3) filling the grating structure with a first material,
(c3) removing first metal deposited on a surface by a lapping process,
(d3) applying the wafer to a frame, such that an underside of the wafer is exposed, thinning back the wafer on a rear side, and applying a metallic layer,
(e3) applying a negative resist on the underside of the wafer, and
(f3) patterning the negative resist in accordance with a LIGA method,
(g3) filling freely developed trenches with a second material.

15. The method of claim 14 , wherein in (e3) a positive resist is applied and is irradiated in accordance with the LIGA method via a mask in a manner aligned with respect to a first structure.

16. A system, unit or apparatus selected from an X-ray-based system appertaining to medical technology, a gantry unit of a computer tomograph, an X-ray micro-CT apparatus, an X-ray optical system for medical radiography (mammography) or angiography, and a baggage or mail scanner, wherein the system, unit or apparatus comprises the grating of claim 1 .

17. A method of non-destructive testing of materials and components or of pharmaceutical screening, wherein the method comprises analyzing an interference image in an interferometer for x-ray imaging by a phase contrast method and/or dark field imaging employing the grating of claim 1 .

18. A method of tumor therapy examination for small animals, wherein the method comprises analyzing an interference image in an interferometer for x-ray imaging by a phase contrast method and/or dark field imaging employing the grating of claim 1 .

19. A method of X-ray imaging, wherein the method comprises analyzing an interference image in an interferometer for x-ray imaging by a phase contrast method and/or dark field imaging employing the grating of claim 1 .

20. The method of claim 19 , wherein the X-ray imaging comprises or involves tomography, radiography, a material investigation, or a light diffuser screen.

Assignees

• Mohr Juergen
• Schulz Joachim
• Reznikova Elena
• Pfeiffer Franz
• Karlsruher Inst Technologie

Inventors

• Mohr Juergen
• Schulz Joachim
• Reznikova Elena
• Pfeiffer Franz

Classifications

• G21K1/06 Primary

  using diffraction, refraction or reflection, e.g. monochromators (G21K1/10, G21K7/00 take precedence) · CPC title

• G21K1/067 Primary

  using surface reflection, e.g. grazing incidence mirrors, gratings (multilayer mirrors G21K1/062) · CPC title

• A61B6/508

  for non-human patients · CPC title

• G21K2207/005

  Methods and devices obtaining contrast from non-absorbing interaction of the radiation with matter, e.g. phase contrast · CPC title

• C25D5/022

  using masking means · CPC title