Opto-electronic hybrid integration platform, optical sub-module, opto-electronic hybrid integration circuit, and process for fabricating platform

• US 6,027,254 A
• Filed: 08/09/1996
• Issued: 02/22/2000
• Est. Priority Date: 08/09/1993
• Status: Expired due to Term

• Current Assignee: Nippon Telegraph and Telephone Corporation
• Original Assignee: Nippon Telegraph and Telephone Corporation
• Inventors: Yoshino, Kaoru, Hashimoto, Toshikazu, Mino, Shinji, Terui, Hiroshi, Sugita, Akio, Ogawa, Ikuo, Moriwaki, Kazuyuki, Kato, Kuniharu, Yanagisawa, Masahiro, Yamada, Yasufumi
• Primary Examiner(s): NGO, HUNG NHAT
• Application Number:
  US08/694,620
• Time in Patent Office: 1,292 Days
• Field of Search: 385/14, 385/88-94, 385/131, 385/132
• US Class Current: 385/88
• CPC Class Codes: G02B 6/42 Coupling light guides with opto-electronic elements
• CPC Class Codes: G02B 6/421 the intermediate optical component consisting of a short length of fibre, e.g. fibre stub
• CPC Class Codes: G02B 6/4219 Mechanical fixtures for holding or positioning the elements relative to each other in the couplings; Alignment methods for the elements, e.g. measuring or observing methods especially used therefor
• CPC Class Codes: G02B 6/4224 using visual alignment markings, e.g. index methods
• CPC Class Codes: G02B 6/4225 by a direct measurement of the degree of coupling, e.g. the amount of light power coupled to the fibre or the opto-electronic element
• CPC Class Codes: G02B 6/4227 Active alignment methods, e.g. procedures and algorithms
• CPC Class Codes: G02B 6/423 using guiding surfaces for the alignment
• CPC Class Codes: G02B 6/4232 using the surface tension of fluid solder to align the elements, e.g. solder bump techniques flip-chip mounting techniques in assembly of semiconductor devices H01L24/81
• CPC Class Codes: G02B 6/4238 Soldering
• CPC Class Codes: G02B 6/4249 comprising arrays of active devices and fibres
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• 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
• CPC Class Codes: H01L 2924/13055 Insulated gate bipolar transistor [IGBT]
• CPC Class Codes: H01L 2924/13091 Metal-Oxide-Semiconductor Field-Effect Transistor [MOSFET]
• CPC Class Codes: H01L 2924/19107 off-chip wires
• CPC Class Codes: H01L 2924/3011 Impedance
• CPC Class Codes: H01S 5/021 Silicon based substrates
• CPC Class Codes: H01S 5/06226 Modulation at ultra-high frequencies
• CPC Class Codes: H01S 5/2068 : obtained by radiation treatment or annealing

Abstract

An opto-electronic hybrid integrated circuit of the present invention satisfy a low-loss optical waveguide function, an optical bench function and a high-frequency electrical wiring function. The circuit includes a substrate such as a silicon substrate, a dielectric optical waveguide part arranged in a recess of the substrate, and an optical device mounting part formed on a protrusion of the substrate. An electrical wiring part is disposed on the dielectric layer. The optical device is mounted on the substrate. An optical sub-module includes the optical device which is possible to mount on the substrate.

Claims

1. A method for producing a platform comprising the steps of:

providing a protruding silicon terrace on a substrate;

forming an optical waveguide under-cladding layer on said substrate, and flattening the surface of said under-cladding layer;

forming a core pattern and an over-cladding layer;

removing said over-cladding layer, said core pattern, and part of said under-cladding layer to expose an upper surface of said silicon terrace and form an electrical wiring part having a surface lower by a desired size than the upper surface of said silicon terrace surface; and

forming a conductor pattern on said electrical wiring part.

2. An opto-electronic hybrid integrated circuit, comprising a packaged platform, said platform including:

an optical waveguide having an under-cladding layer, a core, and an over-cladding layer provided on a substrate;

an optical device silicon terrace functioning as a device mounting part provided as a protrusion adjacent to said optical waveguide;

an electrical wiring part provided adjacent to said silicon terrace and including a dielectric layer and a conductor pattern provided on a surface or inside of said dielectric layer; and

an optical functional device mounted on said optical device silicon terrace having an optical device surface facing down and at least part of the optical device surface contacting an upper surface of the silicon terrace, said optical functional device optically coupled with said optical waveguide and electrically connected with the conductor pattern of said electrical wiring part.

3. An opto-electronic hybrid integrated circuit as claimed in claim 2, wherein said optical waveguide includes at one least one signal line optical waveguide and at least one monitor optical waveguide;

said optical functional device has a signal port and a monitor port formed at positions individually corresponding to said signal line optical waveguide and said monitor optical waveguide on said platform; and

said monitor optical waveguide of said platform and said monitor port of said optical functional device are optically coupled and, at the same time, said optical functional device is disposed on said optical device silicon terrace on said platform with said platform signal optical waveguide and said signal port optically coupled.

4. An opto-electronic hybrid integrated circuit, comprising a platform, said platform including:

an optical waveguide including an under-cladding layer, a core, and an over-cladding layer provided on a substrate;

an optical device silicon terrace functioning as a device mounting part provided as a protrusion adjacent to said optical waveguide;

an electrical wiring part provided adjacent to said silicon terrace and including a dielectric layer and a conductor pattern provided on a surface or inside of said dielectric layer;

an electronic circuit silicon terrace provided as a protrusion on said substrate in said electrical wiring part and functioning as an electronic circuit mounting part;

an optical functional device mounted on said optical device silicon terrace having, an optical device surface facing down and at least part of the optical device surface contacting an upper surface of said optical device silicon terrace, said optical functional device optically coupled with said optical waveguide and electrically connected with the conductor pattern of said electrical wiring part; and

an electronic circuit mounted on said electronic circuit silicon terrace and thermally connected with said electronic circuit silicon terrace.

5. An opto-electronic hybrid integrated circuit as claimed in claim 4, wherein a height of an upper surface of the conductor pattern on said dielectric layer in a vicinity of said electronic circuit silicon terrace is set lower than an upper surface of said electronic circuit silicon terrace, a part of said electronic circuit is contacted with said electronic circuit silicon terrace, and at least a part of an electrode on a surface of the electronic circuit is electrically connected with the conductor pattern on said dielectric layer.

6. An opto-electronic hybrid integrated circuit as claimed in claim 5, wherein said optical functional device has a backslide electrode electrically contacted with a conductor pattern on a recess and a protrusion of a sub-carrier, said sub-carrier having thermal conductive material provided on said conductor pattern of said sub-carrier;

said optical device silicon terrace is divided into two or more sections, and a spacing between said divided silicon terrace sections is filled with said dielectric layer;

a first conductor pattern corresponding to a surface electrode provided on an active layer side surface of said optical functional device and a second conductor pattern corresponding to the backside electrode of said optical functional device are provided on said dielectric layer in a periphery of said optical device silicon terrace;

heights of upper surfaces of said first and second conductor patterns are set lower than an upper surface of said optical device silicon terrace;

said optical functional device is mounted on said sub-carrier and is mounted on said platform with a device surface facing down, a periphery of said optical device surface maintains connection and thermal connection with an upper surface of said silicon terrace;

the surface electrode of said optical functional device and said first conductor pattern are electrically connected through an electroconductive bonding material; and

the backside electrode of said optical functional device and said second conductor pattern on the protrusion of said sub-carrier are electrically connected through an electroconductive bonding material.

7. An opto-electronic hybrid integrated circuit as claimed in claim 6, wherein a distance from an outer side surface of said sub-carrier to the active layer of said optical functional device is set to a desired setting value D in said optical functional device mounted on said sub-carrier;

a guide structure formed of the optical waveguide material is provided in a vicinity of said optical device silicon terrace;

a distance from an inner side surface of said guide structure to a center of the core of said optical waveguide is set to the setting value D; and

said optical functional device is mounted on said optical device silicon terrace while the outer side surface of said sub-carrier maintains contact with the inner side surface of said guide structure.

8. An opto-electronic hybrid electronic circuit as claimed in claim 6, wherein said optical waveguide includes at least one signal line optical waveguide and at least one monitor optical waveguide;

said optical functional device has a signal port and a monitor port formed at positions individually corresponding to said signal line optical waveguide and said monitor optical waveguide on said platform; and

said monitor optical waveguide of said platform and said monitor port of said optical functional device are optically coupled and, at the same time, said optical functional device is disposed on said optical device silicon terrace on said platform with said signal optical waveguide and said signal port optically coupled.

9. An opto-electronic hybrid integrated circuit as claimed in claim 5, wherein said optical functional device has backside electrode electrically contacted with a conductor pattern on a recess and a protrusion of a sub-carrier, said sub-carrier having thermal conductive material provided on said conductor pattern;

said optical device silicon terrace is divided into two or more sections, and has an inclination angle;

a periphery of said divided silicon terrace is filled with said dielectric layer;

on said dielectric layer in a periphery of said silicon terrace, a first conductor pattern corresponding to a surface electrode provided on an active layer side surface of said optical functional device, and a height of said first conductor pattern is set lower than an upper surface of said optical device silicon terrace;

a thin film electrode corresponding to said optical functional device backside electrode is formed on part of the upper surface and the inclined side surface of said optical device silicon terrace , and said thin film electrode is electrically connected with a second conductor pattern provided on said dielectric layer;

wherein said optical functional device is mounted on said sub-carrier and is mounted on said packaged substrate with a device surface facing down, a periphery of the device surface facing down of said optical functional device maintains connection and thermal connection with the upper surface of said optical device silicon terrace;

wherein the surface electrode of said optical functional device and said first conductor pattern are electrically connected through an electroconductive bonding material; and

wherein the backside electrode of said optical functional device and said second conductor pattern are electrically connected through the conductor pattern on the protrusion of said sub-carrier and said thin film electrode on said optical device silicon terrace.

10. An opto-electronic hybrid integrated circuit as claimed in claim 9, wherein a distance from an outer side surface of said sub-carrier to the active layer of said optical functional device is set to a desired setting value D in said optical functional device mounted on said sub-carrier;

a guide structure formed of the optical waveguide material is provided in a vicinity of said optical device silicon terrace;

a distance from an inner side surface of said guide structure to a center of the core of said optical waveguide is set to the setting value D; and

said optical functional device is mounted on said optical device silicon terrace while the outer side surface of said sub-carrier maintains contact with the inner side surface of said guide structure.

11. An opti-electronic hybrid integrated circuit as claimed in claim 9, wherein an other end of a waveguide of individual monitor optical waveguides optically coupled with said optical functional device is conducted to an end of said opto-electronic hybrid platform.

12. An opto-electronic hybrid integrated circuit as claimed in claim 9, wherein two or more optical functional devices are mounted on said opto-electronic hybrid packaged substrate, and a monitor port of each optical functional device is optically coupled with a monitor optical waveguide connecting said optical functional device monitor port and an end of said opto-electronic hybrid platform or said monitor optical waveguide connecting between said two or more optical functional devices.

13. An opto-electronic hybrid integrated circuit as claimed in claim 9, wherein said optical functional device mounted on said opto-eletronic hybrid platform has two or more monitor ports, monitor optical waveguides of a number corresponding to a number of said monitor ports are provided on said opto-electronic hybrid platform;

and

at least one of said monitor ports is set to a width wider than a signal port width, or at least one of signal optical waveguides is set to a width wider than a signal optical waveguide width.

14. An opto-electronic hybrid integrated circuit as claimed in claim 9, wherein said optical waveguide includes at least one signal line optical waveguide and at least one monitor optical waveguide;

said optical functional device has a signal port and a monitor port formed at positions individually corresponding to said signal line optical waveguide and said monitor optical waveguide on said platform; and

said monitor optical waveguide of said platform and said monitor port of said optical functional device are optically coupled and, at the same time, said optical functional device is disposed on said optical device silicon terrace on said platform with said signal optical waveguide and said signal port optically coupled.

15. An opto-electronic hybrid integrated circuit as claimed in claim 5, wherein said optical waveguide includes at least one signal line optical waveguide and at least one monitor optical waveguide;

said optical functional device has a signal port and a monitor port formed at positions individually corresponding to said signal line optical waveguide and said monitor optical waveguide on said platform; and

said monitor optical waveguide of said platform and said monitor port of said optical functional device are optically coupled and, at the same time, said optical functional device is disposed on said optical device silicon terrace on said platform with said signal optical waveguide and said signal port optically coupled.

16. An opto-electronic hybrid integrated circuit as claimed in claim 4, wherein said optical waveguide includes at least one signal line optical waveguide and at least one monitor optical waveguide;

said optical functional device has a signal port and a monitor port formed at positions individually corresponding to said signal line optical waveguide and said monitor optical waveguide on said platform; and

said monitor optical waveguide of said platform and said monitor port of said optical functional device are optically coupled and, at the same time, said optical functional device is disposed on said optical device silicon terrace on said platform with said signal optical waveguide and said signal port optically coupled.

17. An opto-electronic hybrid packaged platform, comprising:

an optical waveguide part, an optical device mounting part, and an electrical wiring part provided on a same substrate, wherein

said optical device mounting part comprises a terrace made of silicon material provided as a protrusion on said substrate;

said electrical wiring part comprises a dielectrical layer formed on said substrate and a conductor pattern formed on a surface or inside of said dielectric layer; and

an upper surface of said conductor pattern on said dielectric layer is set lower than an upper surface of said silicon terrace of said optical device mounting part and at least in a vicinity of a silicon terrace of said electrical wiring part.

18. A platform as claimed in claim 17, wherein said optical waveguide part includes a positioning groove formed on said silicon terrace, and an optical fiber fixed in said positioning groove.

19. A platform as claimed in claim 17, wherein said optical waveguide part comprises an under-cladding layer formed on said substrate, a core, and an over-cladding layer, and a height of a bottom surface of said core of said optical waveguide is set higher than the upper surface of said silicon terrace of said optical device mounting part.

20. A platform as claimed in claim 17, wherein said silicon terrace of said optical device mounting part has a side surface having an inclination angle;

and

a thin film electrode is formed on a surface and the side surface of said silicon terrace of said optical device mounting part, and said thin film electrode is electrically connected to said conductor pattern.

21. A platform as claimed in claim 20, wherein said optical waveguide part includes at least one signal optical waveguide and at least one monitor optical waveguide.

22. A platform as claimed in claim 19, wherein a conductor pattern is formed within said substrate, and said conductor pattern in said substrate and said conductor pattern in or on said dielectric layer are electrically connected.

23. A platform as claimed in claim 17, wherein said substrate is a silicon substrate having a protrusion and a depression;

said optical waveguide part is formed on said depression; and

said conductor pattern is formed on said dielectric layer on said depression.

24. A platform as claimed in claim 17, wherein said silicon terrace of said electrical wiring part is formed on said substrate for mounting an integrated circuit.

25. A platform as claimed in claim 17, wherein said silicon terrace of said optical device mounting part is divided into two or more sections, a space between said divided silicon terrace sections is filled with said dielectric layer, and a conductor pattern is provided on said dielectric layer of said space between said silicon terrace sections.

26. A platform as claimed in claim 25, wherein said optical waveguide part includes a positioning groove formed on said silicon terrace of said optical device mounting part, and an optical fiber fixed in said positioning groove.

27. A platform as claimed in claim 26, wherein said optical waveguide includes at least one signal optical waveguide and at least one monitor optical waveguide.

28. A platform as claimed in claim 25, wherein said optical waveguide part comprises an under-cladding layer formed on said substrate, a core, and an over-cladding layer, and a height of a bottom surface of said core of said optical waveguide part is set higher than an upper surface of said silicon terrace of said optical device mounting part.

29. A platform as claimed in claim 28, wherein said optical waveguide includes at least one signal optical waveguide and at least one monitor optical waveguide.

30. A platform as claimed in claim 25, wherein a conductor pattern is formed within said substrate, and said conductor pattern in said substrate and said conductor pattern in or on said dielectric layer are electrically connected.

31. A platform as claimed in claim 17, wherein said optical waveguide part includes at least one signal optical waveguide and at least one monitor optical waveguide.

32. A platform as claimed in claim 17, wherein a conductor pattern is formed within said substrate, and said conductor pattern in said substrate and said conductor pattern in or on said dielectric layer are electrically connected.

38. A platform as claimed in claim 17, wherein a conductor pattern is formed within said substrate, and said conductor pattern in said substrate and said conductor pattern in or on said dielectric layer are electrically connected.

49. A platform as claimed in claim 29, wherein said optical waveguide part is a dielectric optical waveguide part, and said dielectric layer of said electrical wiring part comprises an under-cladding layer of said dielectric optical waveguide,

wherein said silicon substrate has an average resistivity of 50 ohm-cm or more, said optical waveguide and said dielectric layer are formed of a silica-based optical waveguide, the conductor pattern provided on said dielectric layer is a coplanar wiring comprising a central conductor and a ground conductor, and said dielectric layer has a thickness of 20 μ

m or more.

50. A platform as claimed in claim 49, wherein said silica-based optical waveguide has a total thickness of 120 μ

m or less.

51. A platform as claimed in claim 50, wherein said substrate is a silicon substrate having a depression and a protrusion, said optical waveguide part is formed on said depression, and said dielectric layer is formed on said depression.

33. An opto-electronic hybrid packaged platform, comprising:

an optical waveguide part, an optical device mounting part, and an electrical wiring part provided on a same substrate, wherein

said optical device mounting part comprises a terrace made of silicon material provided as a protrusion on said substrate;

said electrical wiring part comprises a dielectrical layer formed on said substrate and a conductor pattern formed on a surface or inside of said dielectric layer; and

said optical waveguide part includes a positioning groove formed on said silicon terrace, and an optical fiber fixed in said positioning groove.

34. A platform as claimed in claim 33, wherein said substrate is a silicon substrate having a protrusion and a depression;

said optical waveguide part is formed on said depression; and

said conductor pattern is formed on said dielectric layer on said depression.

35. A platform as claimed in claim 33, further comprising an additional terrace formed on said substrate for mounting an integrated circuit.

36. A platform as claimed in claim 33, wherein said optical waveguide part includes at least one signal optical waveguide and at least one monitor optical waveguide.

37. A platform as claimed in claim 36, wherein said substrate is a silicon substrate having a depression and a protrusion, said optical waveguide part is formed on said depression, and said dielectric layer is formed on said depression.

39. A platform as claimed in claim 33, wherein said optical waveguide part includes at least one signal optical waveguide and at least one monitor optical waveguide.

40. An opto-electronic hybrid packaged platform, comprising:

an optical waveguide part, an optical device mounting part, and an electrical wiring part provided on a same substrate, wherein

said optical device mounting part comprises a terrace made of silicon material provided as a protrusion on said substrate;

said electrical wiring part comprises a dielectrical layer formed on said substrate and a conductor pattern formed on a surface or inside of said dielectric layer; and

said optical waveguide part comprises an under-cladding layer formed on said substrate, a core, and an over-cladding layer, and a height of a bottom surface of said core of said optical waveguide part is set higher than an upper surface of said silicon terrace.

41. A platform as claimed in claim 40, wherein said optical waveguide part is a dielectric optical waveguide part, and said dielectric layer of said electrical wiring part comprises an under-cladding layer of said dielectric optical waveguide;

and

a second dielectric layer is stacked on a part of a first dielectric layer, said first dielectric layer including said under-cladding layer of said optical waveguide part, said second dielectric layer including a material different from said optical waveguide part, and a conductor pattern is formed inside or on the surface of said second dielectric layer.

42. A platform as claimed in claim 41, wherein said optical waveguide part has a total thickness of 120 μ

m or less.

43. A platform as claimed in claim 42, wherein said substrate is a silicon substrate having a depression and a protrusion, said optical waveguide part is formed on said depression, and said dielectric layer is formed on said depression.

44. A platform as claimed in claim 40, wherein said substrate is a silicon substrate having a protrusion and a depression;

said optical waveguide part is formed on said depression; and

said conductor pattern is formed on said dielectric layer on said depression.

45. A platform as claimed in claim 40, further comprising an additional terrace formed on said substrate for mounting an integrated circuit.

46. A platform as claimed in claim 40, wherein said optical waveguide part is a dielectric optical waveguide part, and said dielectric layer of said electrical wiring part comprises an under-cladding layer of said dielectric optical waveguide,

wherein said substrate is a silicon substrate, said optical waveguide and said dielectric layer are formed of a silica-based optical waveguide, the conductor pattern formed on said dielectric layer is a coplanar wiring comprising a central conductor and a ground conductor, and said dielectric layer has a thickness of 50 μ

m or more.

47. A platform as claimed in claim 46, wherein said silica-based optical waveguide has a total thickness of 120 μ

m or less.

48. A platform as claimed in claim 47, wherein said substrate is a silicon substrate having a depression and a protrusion, said optical waveguide part is formed on said depression, and said dielectric layer is formed on said depression.

52. A platform as claimed in claim 40, wherein said optical waveguide part includes at least one signal optical waveguide and at least one monitor optical waveguide.

53. A platform as claimed in claim 40, wherein said optical waveguide part is a dielectric optical waveguide part, and said dielectric layer of said electrical wiring part comprises an under-cladding layer of said dielectric optical waveguide,

wherein said substrate is a silicon substrate having a depression and a protrusion, said optical waveguide part is formed on said depression, and said dielectric layer is formed on said depression.

54. An opto-electronic hybrid packaged platform, comprising:

an optical waveguide part, an optical device mounting part, and an electrical wiring part provided on a same substrate, wherein

said optical device mounting part comprises a terrace made of silicon material provided as a protrusion on said substrate;

said electrical wiring part comprises a dielectrical layer formed on said substrate and a conductor pattern formed on a surface or inside of said dielectric layer; and

said optical waveguide part includes an under-clad, a core, and an over-clad formed on said silicon substrate, wherein a height of a bottom surface of said core of said optical waveguide part is higher than an upper surface of said silicon terrace, and wherein said conductor pattern of said electrical wiring part is formed on a surface of said dielectric layer, said dielectric layer having a height which is substantially equal to a surface of said over-clad of said optical waveguide part.

55. A platform as claimed in claim 54, further comprising an additional terrace formed on said substrate for mounting an integrated circuit.

56. An opto-electronic hybrid packaged platform, comprising:

an optical waveguide part, an optical device mounting part, and an electrical wiring part provided on a same substrate, wherein

said optical device mounting part comprises a terrace made of silicon material provided as a protrusion on said substrate;

said electrical wiring part comprises a dielectrical layer formed on said substrate and a conductor pattern formed on a surface or inside of said dielectric layer; and

an upper surface of said conductor pattern on said dielectric layer is set lower than an upper surface of said silicon terrace of said optical device mounting part and at least in the vicinity of a silicon terrace of said electrical wiring part, and wherein said silicon terrace of said optical device mounting part is divided into two or more sections, a space between said divided silicon terrace sections is filled with said dielectric layer, and a conductor pattern is provided on said dielectric layer of said space between said silicon terrace sections.

57. A platform as claimed in claim 56, wherein said substrate is a silicon substrate having a protrusion and a depression;

said optical waveguide part is formed on said depression; and

said conductor pattern is formed on said dielectric layer on said depression.

58. A platform as claimed in claim 56, wherein said silicon terrace of said electrical wiring part is formed on said substrate for mounting an integrated circuit.