Radition detectors and methods for manufacturing them

• US 20020175284A1
• Filed: 03/20/2002
• Published: 11/28/2002
• Est. Priority Date: 03/21/2001
• Status: Active Grant

• Current Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Original Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Inventors: Vilain, Michel
• Granted Patent: US 6,753,526 B2
• Time in Patent Office: Days
• US Class Current: 250/338.1
• CPC Class Codes: B81B 7/0038 using materials for controlling the level of pressure, contaminants or moisture inside of the package, e.g. getters
• CPC Class Codes: G01J 5/04 Casings
• CPC Class Codes: G01J 5/045 Sealings; Vacuum enclosures; Encapsulated packages; Wafer bonding structures; Getter arrangements getter arrangements per se H01L23/26 and H01L21/3221
• CPC Class Codes: G01J 5/20 using resistors, thermistors or semiconductors sensitive to radiation, e.g. photoconductive devices
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 27/14618 Containers
• CPC Class Codes: H01L 27/14632 Wafer-level processed structures
• CPC Class Codes: H01L 27/14649 Infrared imagers
• CPC Class Codes: H01L 27/14687 Wafer level processing
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details

Abstract

The present invention relates to a method of manufacturing radiation detectors, in which these detectors each comprise a set of microdetectors, for example microbolometers, situated under a window that is transparent to said radiation. According to the invention, said detectors are manufactured collectively on a substrate (1), and said method comprises notably the following steps:

the construction of several layers, of which, for each of said detectors, at least one layer (4) is transparent to said radiation and serves as a window, and

the partial elimination of said layers principally under said transparent layer(4), such that said microdetectors (2) are placed, for each of said detectors, in one or more cavities, which are then placed under vacuum or under low pressure.

The invention also relates to various radiation detectors, of which the walls form hermetically sealed cavities each containing one or more microdetectors (2).

Claims

1. A method of manufacturing radiation detectors collectively on a substrate in which said radiation detectors each comprise an assembly of microdetectors under a window that is transparent to radiation, said method comprising:

forming a plurality of layers, wherein for each of said radiation detectors at least one of said plurality of layers is transparent to said radiation and serves as a window; and

partially eliminating at least a portion of said plurality of layers principally under said transparent layer, such that said microdetectors are positioned, for each of said radiation detectors, in one or more cavities; and

placing said one or more cavities under sub-atmospheric pressure.

2. A method of manufacture according to claim 1, further comprising formatting of a peripheral partition surrounding each of said radiation detectors.

3. A method of manufacture according to claim 1, wherein partially eliminating at least a portion of said plurality of layers comprises a process carried out through one or more openings formed in the vicinity of each of said microdetectors.

4. A method of manufacture according to claim 3, wherein placing said one or more cavities under sub-atmospheric pressure comprises a process carried out through said one or more openings, and wherein a surface is formed within said one or more cavities opposite each of said one or more openings that supports a material capable of sealing said one or more openings and said one or more cavities.

5. A method of manufacture according to claim 3, wherein for at least one of said one or more cavities, said openings are formed in said transparent layer.

6. A method of manufacture according to claim 5, wherein placing said one or more cavities under sub-atmospheric pressure comprises a process carried out through said one or more openings, and wherein a surface is formed within said one or more cavities opposite each of said one or more openings that supports a material capable of sealing said one or more openings and said one or more cavities.

7. A radiation detector manufactured by means of a method according to claim 1.

8. A radiation detector according to claim 7, wherein selected internal surfaces of said cavities are covered with a getter.

9. A radiation detector according to claim 8, wherein said selected internal surfaces comprise a portion a surface of said substrate in proximity to at least one of said assembly of microdetectors.

10. A radiation detector according to claim 8, wherein said selected internal surfaces comprise the entire surface of said substrate within each of said cavities.

11. A radiation detector according to claim 7 further comprising a peripheral partition and a network of internal partitions, said window being joined to said peripheral partition and to said network of internal partitions.

12. A radiation detector according to claim 11, wherein at least a portion of said peripheral partitions and a portion of said are network of internal partitions covered with a getter.

13. A radiation detector according to claim 7 further comprising a folded peripheral partition and a network of internal pillars, said window being joined to said folded peripheral partition and to said network of internal pillars.

14. A radiation detector according to claim 13, wherein at least a portion of said folded peripheral partition is covered with a getter.

15. A radiation detector according to claim 7, said at least a portion of said internal pillars, or at least a portion of said peripheral partition, or both, are covered with a getter.

16. A radiation detector according to claim 14, wherein said assembly of microdetectors comprises assembly of microbolometers.

17. A radiation detector according to claim 7, wherein said radiation detector is integrated by a solder bond or by glue into a casing provided with a window transparent to said radiation.

18. An apparatus selected from the group consisting of a measurement apparatus or an observation apparatus, the apparatus comprising at least one radiation detector according to claim 7.

20. A radiation detector according to claim 19, wherein selected internal surfaces of said cavities are covered with a getter.

21. A radiation detector according to claim 20, wherein said selected internal surfaces comprise a portion a surface of said substrate in proximity to at least one of said assembly of microdetectors.

22. A radiation detector according to claim 20, wherein said selected internal surfaces comprise an entire surface of said substrate within each of said cavities.

23. A radiation detector according to claim 19, further comprising a peripheral partition and a network of internal partitions, said window being joined to said peripheral partition and to said network of internal partitions.

24. A radiation detector according to claim 23, wherein at least a portion of said peripheral partitions and a portion of said are network of internal partitions covered with a getter.

25. A radiation detector according to claim 19 further comprising a folded peripheral partition and a network of internal pillars, said window being joined to said folded peripheral partition and to said network of internal pillars.

26. A radiation detector according to claim 25, wherein at least a portion of said folded peripheral partition is covered with a getter.

27. A radiation detector according to claim 25, wherein at least a portion of said network of internal pillars, or at least a portion of said folded peripheral partition, or both, are covered with a getter.

28. A radiation detector according to claim 26, wherein said wherein said assembly of microdetectors comprises assembly of microbolometers.

29. A radiation detector according to claim 19, wherein said radiation detector is integrated by a solder bond or by glue into a casing provided with a window transparent to said radiation.

30. A measurement or observation apparatus comprising at least one radiation detector according to claim 19.

19. A radiation detector comprising an assembly of microdetectors, said radiation detector comprising:

a portion of a substrate,

a peripheral partition surrounding said radiation detector and joined to said portion of substrate; and

a wall adapted to serve as a window for said radiation and joined to said peripheral partition,

wherein said portion of a substrate, said peripheral partition, and said wall define an envelope for said detector, within which are located one or more cavities containing said microdetectors under sub-atmospheric.

31. A radiation detector comprising an assembly of microdetectors under sub-atmospheric pressure in one or more cavities located within an envelope of said radiation detector, said envelope comprising:

a portion of a substrate; and

a wall adapted to serve as a window for said radiation,

wherein said envelope has one or more openings sealed with a sealing material.

32. A radiation detector according to claim 31, wherein selected internal surfaces of said cavities are covered with a getter.

33. A radiation detector according to claim 32, wherein said selected internal surfaces comprise a portion a surface of said substrate in proximity to at least one of said assembly of microdetectors.

34. A radiation detector according to claim 32, wherein said selected internal surfaces comprise an entire surface of said substrate within each of said cavities.

35. A radiation detector according to claim 31 further comprising a peripheral partition and a network of internal partitions, said window being joined to said peripheral partition and to said network of internal partitions.

36. A radiation detector according to claim 35, wherein at least a portion of said peripheral partitions and a portion of said are network of internal partitions covered with a getter.

37. A radiation detector according to claim 31 further comprising a folded peripheral partition and a network of internal pillars, said window being joined to said folded peripheral partition and to said network of internal pillars.

38. A radiation detector according to claim 37, wherein at least a portion of said folded peripheral partition is covered with a getter.

39. A radiation detector according to claim 37, wherein at least a portion of said internal pillars, or at least a portion of said peripheral partition, or both, are covered with a getter.

40. A radiation detector according to claim 38, wherein said assembly of microdetectors comprises assembly of microbolometers.

41. A radiation detector according to claim 31, wherein said radiation detector is integrated by a solder bond or by glue into a casing provided with a window transparent to said radiation.

42. A measurement or observation apparatus comprising at least one radiation detector according to claim 31.