Optical circuit in which fabrication is easy

• US 20020001870A1
• Filed: 02/28/2001
• Published: 01/03/2002
• Est. Priority Date: 06/23/2000
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Soejima, Koji, Oda, Mikio, Kitajo, Sakae
• Granted Patent: US 6,670,208 B2
• Time in Patent Office: Days
• US Class Current: 438/48
• CPC Class Codes: G02B 2006/12104 Mirror; Reflectors or the like
• CPC Class Codes: G02B 6/122 Basic optical elements, e.g. light-guiding paths
• CPC Class Codes: G02B 6/4214 the intermediate optical element having redirecting reflective means, e.g. mirrors, prisms for deflecting the radiation from horizontal to down- or upward direction toward a device G02B6/4246 takes precedence
• CPC Class Codes: G02B 6/4224 using visual alignment markings, e.g. index methods

Abstract

In a method for fabricating an optical circuit, a mirror element with a protection film formed within a die of a semiconductor is connected to a substrate at a predetermined position. The mirror element with the protection film connected to the substrate is peeled from the die of the semiconductor. The protection film is removed to expose a reflection surface of a reflection film of the mirror element.

Claims

1. A method for fabricating an optical circuit, comprising the steps of:

(a) connecting a mirror element with a protection film formed within a die of a semiconductor, to a substrate at a predetermined position;

(b) peeling from said semiconductor die, said mirror element with said protection film connected to said substrate; and

(c) removing said protection film such that a reflection surface of a reflection film of said mirror element is exposed.

2. The method according to claim 1, wherein said mirror element with said protection film is installed in a tip portion of at least one cantilever of said substrate, and

said method further comprises the step of:

mounting an expending and contracting member for moving said tip portion upwardly and downwardly below said mirror element or on a back surface of said tip portion.

3. The method according to claim 1, wherein said expending and contracting member is one of a piezoelectric element, an electric distortion actuator, a magnetic distortion actuator, and a phase transition material.

4. The method according to claim 1, wherein said (b) peeling step comprises the step of:

thinning a thickness of said protection film in a peripheral portion of said mirror element.

5. The method according to claim 1, wherein said (c) removing step comprises the step of:

removing said protection film by a wet etching.

6. The method according to claim 1, wherein said (a) connecting step comprises the steps of:

(d) forming said protection film to cover an inner surface of a concave portion corresponding to said semiconductor die; and

(e) forming a reflection film of said mirror element to at least cover said protection film in said concave portion.

7. The method according to claim 6, wherein said (e) forming step comprises the step of:

forming said reflection film by an electrolytic plating process.

8. The method according to claim 6, wherein said reflection film is one of a gold film, a lamination film of rhodium film-nickel film-gold film, a lamination film of platinum film-nickel film-gold film, a lamination film of palladium film-nickel film-gold film, a lamination film of gold film-nickel film-gold film, a lamination film of nickel film-boron alloy film-nickel film-gold film, a lamination film of nickel film-gold film, a lamination film of chrome film-nickel film gold film, a photosensitive polyimide film, a lamination film of gold film-(Ni—

P) film/Ni film-P film-Au film, and a lamination film of Au film-Pt film-Au film.

9. The method according to claim 6, further comprising the step of:

(f) filling a remaining concave portion after the formation of said reflection film with predetermined material.

10. The method according to claim 9, wherein said predetermined material is a resin composition containing an active energy line polymerization initiator and an active energy line reaction resin.

11. The method according to claim 1, wherein said mirror element has connection auxiliary films in a direction of said reflection surface, and

said (a) connecting step comprises the steps of:

connecting said connection auxiliary films to said substrate; and

connecting said mirror element to said predetermined position of said substrate after said (b) peeling step.

12. The method according to claim 1, wherein said reflection surface of said mirror element has a flat surface.

13. The method according to claim 1, wherein said reflection surface of said mirror element has a concave surface.

14. A method for fabricating an optical circuit comprising the steps of:

(a) connecting a mirror element with a protection film formed within a die of a semiconductor to a substrate at a predetermined position;

(b) peeling from said semiconductor die, said mirror element with said protection film connected to said substrate; and

(c) forming a reflection film of said mirror element on said protection film.

15. The method according to claim 14, wherein said mirror element with said protection film is mounted to a tip portion of at least one cantilever of said substrate, and

said method further comprises the step of:

mounting an expending and contracting member for moving said tip upwardly and downwardly below said mirror element or on a back surface of said tip portion.

16. The method according to claim 14, wherein said expending and contracting member is one of a piezoelectric element, an electric distortion actuator, a magnetic distortion actuator, and a phase transition material.

17. The method according to claim 14, wherein said (b) peeling step comprises the step of:

thinning a thickness of said protection film in a peripheral portion of said mirror element.

18. The method according to claim 14, wherein said (a) connecting step comprises the steps of:

(d) forming said protection film to cover an inner surface of a concave portion corresponding to said semiconductor die; and

(e) forming said mirror element to at least cover said protection film in said concave portion.

19. The method according to claim 18, wherein said (e) forming step comprises the step of:

filling a remaining concave portion after the formation of said mirror element with predetermined material.

20. The method according to claim 19, wherein said predetermined material is a resin composition containing an active energy line polymerization initiator and an active energy line reaction resin.

21. The method according to claim 14, wherein a reflection surface of said mirror element has a flat surface.

22. The method according to claim 14, wherein said reflection surface of said mirror element has a concave surface.

23. A method for fabricating a mirror element comprising the steps of:

(a) forming a protection film to cover an inner surface of a die formed in a semiconductor substrate;

(b) forming a mirror element film to at least cover said protection film in said inner surface of said die; and

(c) peeling from said semiconductor substrate said mirror element film together with said protection film.

24. The method according to claim 23, further comprising the step of:

(d) removing said protection film from said mirror element such that said mirror element film functions as a reflection film.

25. The method according to claim 23, further comprising the step of:

(e) forming a reflection film on said protection film formed on said mirror element film.

26. The method according to claim 25, wherein said reflection film is one of a lamination film of chrome film-gold film, a lamination film of chrome film-aluminum film, a lamination film of chrome film-silver film, a lamination film of chrome film-copper film, a lamination film of chrome film-palladium film, a lamination film of chrome film-titanium film, and a lamination film of chrome film-nickel film.

27. The method according to claim 24, wherein said (a) forming step comprises the steps of:

(f) forming said protection film to cover said inner surface of said die formed in said semiconductor; and

(g) forming said mirror element film to at least cover said protection film in said inner surface of said die.

28. The method according to claim 27, wherein said (g) forming step comprises the step of:

forming said mirror element film by an electrolytic plating process.

29. The method according to claim 27, wherein said mirror element film is one of a gold film, a lamination film of rhodium film-nickel film-gold film, a lamination film of platinum film-nickel-film gold film, a lamination film of palladium film nickel film-gold film, a lamination film of gold film-nickel film-gold film, a lamination film of nickel film-boron alloy film-nickel film-gold film, a lamination film of nickel film-gold film, a lamination film of chrome film-nickel film-gold film, a photosensitive polyimide film, a lamination film of gold film-(Ni—

P) film/Ni film-P film-Au film, and a lamination film of Au film-Pt film-Au film.

30. The method according to claim 27, further comprising the step of:

(h) filling a remaining concave portion after the formation of said mirror element film with predetermined material.

31. The method according to claim 30, wherein said predetermined material is one of a resin composition containing an active energy line polymerization initiator and an active energy line reaction resin.

32. The method according to claim 31, wherein said active energy line reaction resin is one of phenol novolak type epoxy resin, cresol/volak type epoxy resin, glycylamine type epoxy resin and biphenyl type epoxy resin.

33. The method according to claim 31, wherein said active energy line reaction resin is substance obtained by reacting unsaturated-base-acid such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, maleic acid monomethyl, maleic acid monopropyl, maleic acid monobutyl, sorbic acid with epoxy resin having fluorene skeleton or epoxy resin portion of bromide of epoxy resin having fluorene skeleton, and by making into ester.

34. The method according to claim 31, wherein said active energy line polymerization initiator is one kind or two kinds or more of a benzophenone class, a benzildi-methylkethal class and a compound of a thio-xanthone system.

35. The method according to claim 23, wherein said (a) forming step further comprises the step of:

etching a silicon substrate to form a concave portion corresponding to said die.

36. The method according to claim 35, wherein an inner surface of said concave portion has one of a (100) surface and a (111) surface.

37. The method according to claim 35, wherein said concave portion is one of a pyramid shape and a triangular pole shape in which both ends are cut down.

38. The method according to claim 23, wherein said (c) peeling step comprises the step of:

thinning said protection film in a peripheral portion corresponding to said mirror element film.

39. The method according to claim 32, wherein said (c) stripping step comprises the step of:

peeling said mirror element film from said die of said semiconductor after said mirror element film is connected to the substrate.

40. The method according to claim 39, wherein said mirror element film has connection film portions used to connect to said substrate in a direction orthogonal to an optical axis at a time of a usage.