Structure for electrically connecting a first body of semiconductor material overlaid by a second body of semiconductor material, composite structure using the electric connection structure, and manufacturing process thereof

US 20010038148A1
Filed: 04/27/2001
Published: 11/08/2001
Est. Priority Date: 04/28/2000
Status: Active Grant

First Claim

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1. An electric connecting structure for connecting a first body of semiconductor material overlaid by a second body of semiconductor material, the connecting structure comprising:

a plug region extending through a portion of said second body and made of semiconductor material;

an insulation region surrounding laterally said plug region; and

a first electromechanical connection region of electrically conductive material arranged between said first body and said second body and in electrical contact with said plug region and with conductive regions of said first body.

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Abstract

An electric connection structure connecting a first silicon body to conductive regions provided on the surface of a second silicon body arranged on the first body. The electric connection structure includes at least one plug region of silicon, which extends through the second body; at least one insulation region laterally surrounding the plug region; and at least one conductive electromechanical connection region arranged between the first body and the second body, and in electrical contact with the plug region and with conductive regions of the first body. To form the plug region, trenches are dug in a first wafer and are filled, at least partially, with insulating material. The plug region is fixed to a metal region provided on a second wafer, by performing a low-temperature heat treatment which causes a chemical reaction between the metal and the silicon. The first wafer is thinned until the trenches and electrical connections are formed on the free face of the first wafer.

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1. An electric connecting structure for connecting a first body of semiconductor material overlaid by a second body of semiconductor material, the connecting structure comprising:
- a plug region extending through a portion of said second body and made of semiconductor material;
  
  an insulation region surrounding laterally said plug region; and
  
  a first electromechanical connection region of electrically conductive material arranged between said first body and said second body and in electrical contact with said plug region and with conductive regions of said first body.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
- - 2. The electric connection structure of claim 1, wherein said plug region extends throughout a thickness of said second body and has a first face and a second face, said first face being in contact with said first electromechanical connection region;
    - and further comprising a contact region of electrically conducting material in contact with said second face of said plug region.
  - 3. The electric connection structure of claim 2, further comprising an electric connection line extending above said second body and having a first end forming said contact region.
  - 4. The electric connection structure of claim 3, wherein said electric connection line has a second end in electrical contact with a conductive region of said second body.
  - 5. The electric connection structure of claim 3, wherein said electric connection line has a second end in electrical contact with a contact region formed on a third body fixed to said second body.
  - 6. The electric connection structure of claim 2, for electrically connecting said second body to a third body of semiconductor material arranged on said second body, wherein said contact region further comprises at least one second electromechanical connection region made of a material resulting from the chemical reaction of said semiconductor material with a metal, said second electromechanical connection regions being arranged between said second body and said third body.
  - 7. The electric connection structure of claim 1, for a second body comprising a substrate region and an epitaxial region arranged on each other and partially insulated from one another by insulating regions, wherein:
    - said plug region further comprises a first plug portion extending throughout the thickness of said substrate region, and a second plug portion formed inside said epitaxial region, said second plug portion being aligned and in direct electrical contact with said first plug portion;
      
      said insulation region further comprises a first insulation portion laterally surrounding said first plug portion, and a second insulation portion laterally surrounding said second plug portion;
      
      a contact region of electrically conducting material extends on a free face of said substrate region in electrical contact with said first plug portion;
      
      and said second plug portion faces and is in direct electrical contact with said first electromechanical connection region.
  - 8. The electric connection structure of claim 1, for a second body comprising a substrate region and an epitaxial region arranged on one another and reciprocally insulated by insulating regions, wherein said substrate region has a smaller area than said epitaxial region, said plug region extends throughout the thickness of said epitaxial region, and has a first face and a second face, said first face being in contact with said first electromechanical connection region, and said second face being in direct contact with at least one electric connection region of electrically conducting material.
  - 9. The electric connection structure according to claim 1, wherein said insulation region comprises a trench having a closed shape filled at least partially with insulating material.
  - 10. The electric connection structure according to claim 1, wherein said first electromechanical connection region is made of a material resulting from the chemical reaction of said semiconductor material with a metal.
  - 11. The electric connection structure according to claim 1, wherein said first electromechanical connection region is made of a metal resulting from the chemical reaction of silicon with a metal chosen from among a group comprising gold, palladium, titanium, and nickel.

12. A composite structure comprising:
- a first body of semiconductor material;
  
  a second body of semiconductor material arranged on said first body); and
  
  an electric connection structure, including;
  
  a plug region extending through a portion of said second body and made of semiconductor material, an insulation region laterally surrounding said plug region, and a first electromechanical connection region of electrically conductive material arranged between said first body and said second body and in electrical contact with said plug region and with conductive regions of said first body.
- View Dependent Claims (13, 14, 15, 16, 17, 18, 19)
- - 13. The composite structure according to claim 12, wherein said plug region extends throughout the thickness of said second body and has a first face and a second face, said first face being in contact with said first electromechanical connection region;
    - further comprising a contact region of electrically conducting material, in contact with said second face of said plug region; and
      
      wherein said first body houses an electronic circuit); and
      
      said second body houses a micro-electromechanical device comprising a fixed part and a mobile part separated from each other by at least one delimitation trench extending through said second body.
  - 14. The composite structure of claim 13, further comprising an external electric connection wire bonded to said contact region.
  - 15. The composite structure of claim 13, wherein said electric connection structure further comprises an electric connection line extending above said second body and having a first end forming said contact region, and a second end in electrical contact with said micro-electromechanical device.
  - 16. The composite structure of claim 13, further comprising a third body fixed to said second body, said electric connection structure further comprising an electric connection line having a first end forming said contact region and a second end in electrical contact with a contact region formed on said third body.
  - 17. The composite structure of claim 16, wherein said third body is a slider, and said composite structure forms an actuator unit for micrometric position regulation of a hard-disk driver.
  - 18. The composite structure of claim 12, wherein the first body of semiconductor material further houses a first electronic circuit;
    - further comprising a third body of semiconductor material and housing a second electronic circuit, said third body fixed to said second body; and
      
      the electric connection structure, wherein;
      
      said plug region includes a first face and a second face, said plug region connecting together said first and second electronic circuits, said first electromechanical connection region arranged between said first body and said second body is further in electrical contact with said first face of said plug region, and further comprising a contact region of electrically conducting material in contact with said second face of said plug region, the contact region having at least one second electromechanical connection region made of a material resulting from the chemical reaction of said semiconductor material with a metal, said second electromechanical connection regions being arranged between said second body and said third body.
  - 19. The composite structure of claim 18, further comprising a sealing region having a closed shape and arranged between said first and said second bodies, outside one of said first and second electronic circuits.

20. A composite structure comprising:
- a first body of semiconductor material;
  
  a second body of semiconductor material arranged on said first body and comprising a an epitaxial region housing a micro-electromechanical device having a fixed part and a mobile part separated from one another by a delimitation trench extending through said epitaxial region and a substrate region forming a cap region and arranged over the mobile part of said epitaxial region, said epitaxial region and said substrate region being arranged on each other and partially insulated from one another by first and second insulating regions; and
  
  an electric connection structure, including;
  
  a first plug portion formed of semiconductor material and extending throughout the thickness of said substrate region, a second plug portion formed of semiconductor material and formed inside said epitaxial region, said second plug portion being aligned and in direct electrical contact with said first plug portion and further facing and in direct electrical contact with a first electromechanical connection region, said first electromechanical connection region being formed of electrically conductive material arranged between said first body and said second body and in electrical contact with conductive regions of said first body, said first insulation portion laterally surrounding said first plug portion, and said second insulation portion laterally surrounding said second plug portion; and
  
  a contact region of electrically conducting material extending on a free face of said substrate region in electrical contact with said first plug portion.

21. A composite structure comprising:
- a first body of semiconductor material;
  
  a second body of semiconductor material arranged on said first body and comprising an epitaxial region housing a micro-electromechanical device comprising a fixed part and a mobile part separated from one another by at least one delimitation trench extending through said epitaxial region and a substrate region forming a cap region which has larger dimensions than said mobile part and is fixed to said fixed part, said epitaxial region and said substrate region overlaid to each other and reciprocally insulated from one another by insulating regions; and
  
  an electric connection structure, including;
  
  a plug region extending throughout the thickness of said epitaxial region of said second body and made of semiconductor material, said plug region having a first face and a second face, said first face being in contact with a first electromechanical connection region, and said second face being in direct contact with at least one electric connection region of electrically conducting material, said first electromechanical connection region of electrically conductive material arranged between said first body and said second body and in electrical contact with said plug region and with conductive regions of said first body, and an insulation region laterally surrounding said plug region.

22. A process for manufacturing a composite structure, comprising:
- forming a plug region surrounded by an insulation region extending through a first wafer of semiconductor material;
  
  forming an electromechanical-connection region of conductive material on a second wafer of semiconductor material, and aligned with said plug region;
  
  bringing said first wafer and said second wafer close together, bringing said plug region into contact with said electromechanical-connection; and
  
  fixing said first wafer and said second wafer through said electromechanical connection region.
- View Dependent Claims (23, 24, 25, 26, 27, 28, 29)
- - 23. The process of claim 22, further comprising:
    - initially forming said insulation region in said first wafer, said insulation region partially extending inside said first wafer from a surface of said first wafer and laterally delimiting said one plug region;
      
      turning said first wafer upside down to bring said surface of said first wafer in a facing position with said second wafer; and
      
      thinning said first wafer until said insulation region.
  - 24. The process of claim 23, wherein said forming said insulation region further comprises:
    - forming isolation trenches in said first wafer; and
      
      at least partially filling said isolation trenches with insulating material.
  - 25. The process of claim 24, further comprising forming trenches delimiting a micro-electromechanical structure in said first wafer, and forming an electronic circuit in said second wafer before forming said electromechanical-connection region.
  - 26. The process of claim 22, further comprising:
    - forming a first insulation portion of said insulation region in a substrate of semiconductor material, said first insulation portion partially extending inside said substrate from a surface of said substrate, and laterally delimiting a first plug portion of said plug region;
      
      growing an epitaxial layer from said surface of said substrate;
      
      forming at least one second insulation portion of said insulation region in said epitaxial layer, said second insulation portion extending throughout the thickness of said epitaxial layer and delimiting a second plug portion of said plug region which is substantially aligned and in electrical contact with said first plug portion;
      
      fixing said second plug portion to said second wafer;
      
      thinning said substrate until said first insulation portion; and
      
      forming contact regions on a free face of said substrate.
  - 27. The process of claim 22, further comprising:
    - on a substrate, growing an epitaxial layer;
      
      forming said insulation region in said epitaxial layer, said insulation region extending throughout the thickness of said epitaxial layer and delimiting said plug region;
      
      forming a device to be protected in said epitaxial layer;
      
      fixing said epitaxial layer of said first wafer to said second wafer through said plug region;
      
      selectively removing said substrate to form a cap region covering said device to be protected, and freeing said plug region; and
      
      forming contact regions above said plug region.
  - 28. The process according to claim 22, wherein said step of fixing said first wafer to said second wafer is carried out in vacuum conditions and further comprises forming a sealing region between said first wafer and said second wafer.
  - 29. The process according to claim 22, wherein said conductive material of said electromechanical connection region is a metal, and said fixing further comprises causing said metal of said electromechanical-connection structure to react with said semiconductor material of said plug region.

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Current Assignee
STMicroelectronics Incorporated (STMicroelectronics NV)
Original Assignee
STMicroelectronics SRL (STMicroelectronics NV)
Inventors
Mastromatteo, Ubaldo, Bombonati, Mauro, Aina, Roberto, Ghironi, Fabrizio

Granted Patent

US 6,504,253 B2
Time in Patent Office

Days
Field of Search
US Class Current

257/758
CPC Class Codes

B81C 1/00238   Joining a substrate with an...

B81C 2201/019   Bonding or gluing multiple ...

H01L 21/76898   formed through a semiconduc...

H01L 2224/05571   the external layer being di...

H01L 2224/05573   Single external layer

H01L 2224/16145   the bodies being stacked

H01L 2225/06513   Bump or bump-like direct el...

H01L 2225/06541   Conductive via connections ...

H01L 23/481   Internal lead connections, ...

H01L 25/0657   Stacked arrangements of dev...

H01L 25/50   Multistep manufacturing pro...

H01L 2924/01322   Eutectic Alloys, i.e. obtai...

Structure for electrically connecting a first body of semiconductor material overlaid by a second body of semiconductor material, composite structure using the electric connection structure, and manufacturing process thereof

First Claim

3 Assignments

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Accused Products

Abstract

25 Citations

29 Claims

Specification

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Structure for electrically connecting a first body of semiconductor material overlaid by a second body of semiconductor material, composite structure using the electric connection structure, and manufacturing process thereof

First Claim

3 Assignments

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0 Petitions

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Accused Products

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Abstract

25 Citations

29 Claims

Specification

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Solutions

Use Cases

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