Electrical device including a functional element in a cavity

• US 9,676,608 B2
• Filed: 08/18/2014
• Issued: 06/13/2017
• Est. Priority Date: 01/25/2008
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Kojima, Akihiro, Sugizaki, Yoshiaki, Shimooka, Yoshiaki
• Primary Examiner(s): Willis, Tremesha S
• Application Number:
  US14/462,262
• Publication Number:
  US 20140353777A1
• Time in Patent Office: 1,030 Days
• Field of Search: 174260, 174250, 174255, 174256, 174258
• CPC Class Codes: B81B 2201/0221 Variable capacitors
• CPC Class Codes: B81B 2203/04 Electrodes
• 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: B81C 1/00476 removing a sacrificial layer B81C1/00912 takes precedence

Abstract

A substrate includes a functional element. An insulating first film forms a cavity which stores the functional element, together with the substrate, and includes a plurality of through-holes. An insulating second film covers the plurality of through-holes, is formed on the first film, and has a gas permeability which is higher than that of the first film. An insulating third film is formed on the second film and has a gas permeability which is lower than the second film. An insulating fourth film is formed on the third film and has an elasticity which is larger than the third film.

Claims

1. An electrical device, comprising:

a functional element formed above a substrate, the functional element comprising a movable part capable of moving;

an insulating first film formed above the functional element to have a space between the first film and the movable part, the first film including a plurality of through-holes, and comprising an inorganic film;

an insulating second film formed above the insulating first film, and straddling the through-holes;

an insulating third film formed above the insulating second film; and

an insulating fourth film formed above the insulating third film, the fourth film comprising an organic film,

wherein a water permeability of the second film is higher than that of the third film.

2. The device of claim 1, wherein

the first film is a silicon compound consisting mainly of Si—

O bonds,

the second film is a resin,

the third film is a silicon compound consisting mainly of Si—

N bonds, and

the insulating fourth film is a resin.

3. The device of claim 1, wherein the third film comprises aluminum.

4. The device of claim 1, wherein the second film is configured to cover the plurality of the through-holes.

5. The device of claim 1, further comprising an insulating fifth film configured to cover a side surface of the second film and comprising an inorganic film.

6. The device of claim 5, wherein the fifth film and the third film are films formed of the same material.

7. The device of claim 5, further comprising an electrode formed outside the second film.

8. The device of claim 1, wherein the fourth film is one of an epoxy resin and a polyimide resin.

9. The device of claim 1, wherein shapes of the through-holes are taper shapes.

10. The device of claim 1, further comprising a sixth film formed between the second film and the third film.

11. The device of claim 10, wherein the sixth film is a oxide film.

12. The device of claim 1, further comprising:

a wiring provided outside of the space; and

a bump provided above the wiring, the bump being electrically connected to the wiring,

wherein the third film is extended outside of the space, the third film includes an opening corresponding to the wiring.

13. The device of claim 12, further comprising a metal film provided between the bump and the wiring.

14. The device of claim 12, wherein the metal film adheres to the bump and wiring.

15. The device of claim 1, further comprising:

a wiring provided outside of the space; and

a bump provided above the wiring, the bump being electrically connected to the wiring,

wherein the fourth film is extended outside of the space, the fourth film includes an opening corresponding to the wiring.

16. The device of claim 15, further comprising a metal film provided between the bump and the wiring.

17. The device of claim 16, wherein the metal film adheres to the bump and wiring.

18. The device of claim 1, wherein the movable part has a conductive material.

19. An electrical device, comprising:

a functional element formed above a substrate, the functional element comprising a movable part capable of moving;

an insulating first film formed above the functional element to have a space between the first film and the movable part, the first film including a plurality of through-holes, and comprising an inorganic film;

an insulating second film formed above the insulating first film, and provided in the through-holes, the second film straddling the through-holes; and

an insulating third film formed above the insulating second film,

wherein a water permeability of the second film is higher than that of the third film.

20. The device of claim 19, wherein

the first film is a silicon compound consisting mainly of Si—

O bonds,

the second film is a resin,

the third film is a silicon compound consisting mainly of Si—

N bonds, and

an insulating fourth film, formed above the insulating third film, is a resin.

21. The device of claim 19, wherein the third film comprises aluminum.

22. The device of claim 19, wherein the second film is configured to cover the plurality of the through-holes.

23. The device of claim 19, further comprising an insulating fifth film configured to cover a side surface of the second film and comprising an inorganic film.

24. The device of claim 23, wherein the fifth film and the third film are films formed of the same material.

25. The device of claim 23, further comprising an electrode formed outside the second film.

26. The device of claim 19, wherein an insulating fourth film, formed above the third insulating film, is one of an epoxy resin and a polyimide resin.

27. The device of claim 19, wherein shapes of the through-holes are taper shapes.

28. The device of claim 19, further comprising a sixth film formed between the second film and the third film.

29. The device of claim 28, wherein the sixth film is a oxide film.

30. The device of claim 19, further comprising:

a wiring provided outside of the space; and

a bump provided above the wiring, the bump being electrically connected to the wiring,

wherein the third film is extended outside of the space, the third film includes an opening corresponding to the wiring.

31. The device of claim 30, further comprising a metal film provided between the bump and the wiring.

32. The device of claim 31, wherein the metal film adheres to the bump and wiring.

33. The device of claim 19, further comprising:

a wiring provided outside of the space; and

a bump provided above the wiring, the bump being electrically connected to the wiring,

wherein an insulating fourth film, formed above the third insulating film, is extended outside of the space, the fourth film includes an opening corresponding to the wiring.

34. The device of claim 33, further comprising a metal film provided between the bump and the wiring.

35. The device of claim 34, wherein the metal film adheres to the bump and wiring.

36. The device of claim 19, wherein the movable part has a conductive material.

37. An electrical device, comprising:

a functional element formed above a substrate, the functional element comprising a movable part capable of moving;

an insulating first film formed above the functional element to have a space between the first film and the movable part, the first film including a plurality of through-holes, and comprising an inorganic film;

an insulating second film formed above the insulating first film, and straddling the through-holes; and

an insulating third film formed above the insulating second film, the third film comprising an organic film.