Microstructure comprising a surface which is functionalized through the localized deposit of a thin layer and production method thereof

• US 7,196,385 B2
• Filed: 08/25/2003
• Issued: 03/27/2007
• Est. Priority Date: 08/26/2002
• Status: Expired due to Fees

• Current Assignee: Alchimer S.A.
• Original Assignee: Alchimer S.A., Tronic's Microsystems
• Inventors: Bureau, Christophe, Perruchot, Francois, Kergueris, Christophe
• Primary Examiner(s): Huynh; Andy
• Assistant Examiner(s): TAYLOR, EARL N
• Application Number:
  US10/524,560
• Publication Number:
  US 20050253206A1
• Time in Patent Office: 1,310 Days
• Field of Search: 257/419, 438/53, 977/733
• US Class Current: 257/419
• CPC Class Codes: A61B 5/00 Measuring for diagnostic purposes radiation diagnosis A61B6/00; diagnosis by ultrasonic, sonic or infrasonic waves A61B8/00; Identification of persons
• CPC Class Codes: B29C 2043/5825 dimensions or shape, e.g. size, thickness
• CPC Class Codes: B81B 2201/0214 Biosensors; Chemical sensors
• CPC Class Codes: B81B 2201/0235 Accelerometers
• CPC Class Codes: B81B 2201/0264 Pressure sensors
• CPC Class Codes: B81B 2201/06 Bio-MEMS
• CPC Class Codes: B81B 2203/0127 Diaphragms, i.e. structures separating two media that can control the passage from one medium to another; Membranes, i.e. diaphragms with filtering function
• CPC Class Codes: B81B 3/0094 Constitution or structural means for improving or controlling physical properties not provided for in B81B3/0067 - B81B3/0091
• CPC Class Codes: G01L 9/0042 Constructional details associated with semiconductive diaphragm sensors, e.g. etching, or constructional details of non-semiconductive diaphragms details about the integration or bonding of piezoresistor in or on the diaphragm G01L9/0052 and G01L9/0057 respectively
• 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 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/181 Encapsulation
• CPC Class Codes: Y10S 977/733 Nanodiaphragm

Abstract

An electromechanical microstructure including a first mechanical part formed in a first electrically conductive material, and which includes a zone deformable in an elastic manner having a thickness value and an exposed surface, and a first organic film having a thickness, present on all of the exposed surface of the deformable zone. The thickness of the first film is such that the elastic response of the deformable zone equipped with the first film does not change by more than 5% compared to the response of the bare deformable zone, or the thickness of the first film is less than ten times the thickness of the deformable zone.

Claims

1. An electromechanical microstructure comprising:

a first mechanical part formed in a first electrically conductive material, and which comprises (1) a zone deformable in an elastic manner having a thickness value and an exposed surface and (2) a first organic film having a thickness, present on a whole of the exposed surface of the deformable zone,

wherein the first organic film is bonded in a covalent manner to the exposed surface of the deformable zone and formed from an electro-initiated reaction;

an annular zone at a surface of the first mechanical part, surrounding the exposed surface, having itself a surface and formed in a second electrically conductive material, different in a sense of the electro-initiated reaction from the first electrically conductive material of the first mechanical part; and

a second organic film present on the surface of the annular zone, the second organic film formed in a material that may be deposited from an electro-initiated chemical reaction.

2. The electromechanical microstructure according to claim 1, wherein the thickness of the first organic film is such that elastic response of the deformable zone equipped with the first organic film does not change by more than 5% compared to a response of a bare deformable zone, or wherein the thickness of the first organic film is less than ten times a thickness of the deformable zone.

3. The electromechanical microstructure according to claim 2, wherein the thickness of the first organic film is such that elastic response of the deformable zone equipped with the first organic film does not change by more than 1%.

4. The electromechanical microstructure according to claim 2, wherein a level of cover of the exposed surface by the first organic film is greater than 60%.

5. The electromechanical microstructure according to claim 2, wherein the first electrically conductive material constituting the first mechanical part is a doped semi-conductor, the annular zone is formed in a second material formed by doping of type opposite to that of the first material.

6. The electromechanical microstructure according to claim 1, wherein the first mechanical part comprises one or plural contact points in a position exterior to the annular zone.

7. The electromechanical microstructure according to claim 1, wherein the first mechanical part comprises one or plural first contact points having a surface formed in a third electrically conductive material, different in a sense of the electro-initiated reaction from the first electrically conductive material, in a position exterior to the annular zone, and wherein a third organic film is present on the surface of the first contact points, the third organic film formed in a material that may be deposited from an electro-initiated chemical reaction.

8. The electromechanical microstructure according to claim 7, further comprising a second part, electrically insulated from and mechanically integral with the first mechanical part comprising one or plural second contact points having a surface formed in a material different in the sense of the electro-initiated reaction from a material constituting the second part, and wherein a fourth organic film is present on the surface of the second contact points, the fourth organic film formed in a material that may be deposited from an electro-initiated chemical reaction.

9. The electromechanical microstructure according to claim 8, further comprising a third part, mechanically integral with the first mechanical part and the second part, electrically insulated from the first mechanical part, formed in an electrically conductive material, and wherein the second part and the third part are electrically connected.

10. The electromechanical microstructure according to claim 9, wherein the mechanical first part includes a first layer of monocrystalline silicon, and wherein the first mechanical part and second part are integral with a same insulating layer, and wherein the third part includes a second layer of silicon on which lies the insulating layer.

11. The electromechanical microstructure according to claim 10, wherein the insulating layer comprises a recess situated immediately underneath the deformable zone.

12. A wafer comprising a series of the electromechanical microstructures according to claim 9, and comprising a first shared electrode electrically connecting all of the first mechanical parts of the series of the electromechanical microstructures and a second shared electrode formed on the surface of the wafer electrically connected to the second mechanical part.

13. A wafer comprising a series of the electromechanical microstructures according to claim 8, and comprising a first shared electrode electrically connecting all of the first mechanical parts of the series of the electromechanical microstructures and a second shared electrode formed on the surface of the wafer electrically connected to the second mechanical part.

14. The electromechanical microstructure according to claim 7, wherein the first electrically conductive material constituting the first mechanical part is a doped semi-conductor, and wherein a doping of type opposite to that of the first material defines an electrode contact at a surface of the first mechanical part outside of the exposed surface.

15. The electromechanical microstructure according to claim 7, wherein the second organic film is a film with biocompatibility and non-cyctotoxicity functions.

16. A pressure sensor incorporating the electromechanical microstructure according to claim 15.

17. A wafer comprising a series of the electromechanical microstructures according to claim 7, and comprising a first shared electrode electrically connecting all of the first mechanical parts of the series of the electromechanical microstructures.

18. A microsystem comprising the electromechanical microstructure according to claim 7, electrically assembled with a front face turned round on an interconnection support comprising an opening leading out opposite the deformable zone of the microstructure, a film of the annular zone of the microstructure being in an insulating thermofusible material and coming into contact with a substrate of the support to form a sealing joint around the deformable zone of the microstructure, the film of contact points of the microstructure being in a conductive thermofusible material and coming into contact with pads of the support to form a mechanical and electrical connection between the microstructure and the support.

19. A The microsystem according to claim 18, wherein contact points of the support comprise a film formed in a conductive thermofusible material obtained from an electro-initiated reaction, the pads coming into contact with films of the contact points of the microstructure to ensure an electrical and mechanical connection between the support and the microstructure by heat sealing.

20. The electromechanical microstructure according to claim 2, wherein the first organic film is in a material such that the exposed surface of the deformable zone covered with this film has biocompatibility, non cyctotoxicity, and/or anti-adhesion or cellular anti-proliferation functions.

21. The electromechanical microstructure according to claim 1, wherein the thickness of the first organic film is such that elastic response of the deformable zone equipped with the first organic film does not change by more than 1%.

22. The electromechanical microstructure according to claim 21, wherein the first organic film includes a layer of a molecule of fixed length.

23. The electromechanical microstructure according to claim 1, wherein a level of cover of the exposed surface by the first organic film is greater than 60%.

24. The electromechanical microstructure according to claim 23, wherein a level of cover of the exposed surface by the first organic film is greater than 90%.

25. The electromechanical microstructure according to claim 1, wherein the first electrically conductive material constituting the first mechanical part is a doped semi-conductor, the annular zone is formed in a second material formed by doping of type opposite to that of the first material.

26. The electromechanical microstructure according to claim 25, wherein the first mechanical part comprises one or plural first contact points having a surface formed in a third electrically conductive material, different in a sense of the electro-initiated reaction from the first and second electrically conductive materials, in a position exterior to the annular zone, and wherein a third organic film is present on the surface of the first contact points, the third organic film formed in a material that may be deposited from an electro-initiated chemical reaction.

27. The electromechanical microstructure according to claim 26, further comprising a second part, electrically insulated from and mechanically integral with the first mechanical part comprising one or plural second contact points having a surface formed in a material different in the sense of the electro-initiated reaction from a material constituting the second part, and wherein a fourth organic film is present on the surface of the second contact points, the fourth organic film formed in a material that may be deposited from an electro-initiated chemical reaction.

28. The electromechanical microstructure according to claim 27, wherein the first mechanical part includes a first layer of silicon, and wherein the first mechanical part and second part are integral with a same insulating layer.

29. The electromechanical microstructure according to claim 28, wherein the insulating layer comprises a recess situated immediately underneath the deformable zone.

30. A wafer comprising a series of the electromechanical microstructures according to claim 26, and comprising a first shared electrode electrically connecting all of the first mechanical parts of the series of the electromechanical microstructures, and wherein a polarity necessary to electro-initiate the second organic film corresponds to an open sense of a diode created by the doping in a sense from the deformable zone towards the annular zone of the first mechanical part.

31. A wafer comprising a series of the electromechanical microstructures according to claim 26, and comprising a first shared electrode electrically connecting all of the annular zones between them, and wherein a polarity necessary to electro-initiate the first and third organic films is identical and corresponds to an open sense of a diode created by the doping in a sense annular zone to the deformable zone of the first mechanical part.

32. A wafer comprising a series of the electromechanical microstructures according to claim 25, and comprising a first shared electrode electrically connecting all of the annular zones between them, and wherein a polarity necessary to electro-initiate the first organic film corresponds to an open sense of a diode created by the doping in a sense annular zone towards the deformable zone of the first mechanical part.

33. A wafer comprising a series of the electromechanical microstructures according to claim 25, and comprising a first shared electrode electrically connecting all of the first mechanical parts of the series of the electromechanical microstructures, and wherein a polarity necessary to electro-initiate the second organic film corresponds to an open sense of a diode created by the doping in a sense from the deformable zone towards the annular zone of the first mechanical part.

34. The electromechanical microstructure according to claim 1, wherein the first electrically conductive material constituting the first mechanical part is a doped semi-conductor, and wherein a doping of type opposite to that of the first material defines an electrode contact at a surface of the first mechanical part outside of the exposed surface.

35. The electromechanical microstructure according to claim 1, wherein the first organic film is in a material such that the exposed surface of the deformable zone covered with this film has biocompatibility, non cyctotoxicity, and/or anti-adhesion or cellular anti-proliferation functions.

36. The electromechanical microstructure according to claim 1, wherein the second organic film is a film with biocompatibility and non-cyctotoxicity functions.

37. A wafer comprising a series of the electromechanical microstructures according to claim 1, and comprising a first shared electrode electrically connecting all of the first mechanical parts of the series of the electromechanical microstructures.

38. A microsystem comprising the electromechanical microstructure according to claim 1, electrically assembled with a front face turned round on an interconnection support comprising an opening facing the deformable zone of the microstructure.

39. A The microsystem according to claim 38, wherein the support is formed from a wafer in silicon, and comprising a probe connected to a dedicated electronic component itself assembled on the support.

40. A microsystem comprising the electromechanical microstructure according to claim 1, electrically assembled with a front face turned round on an interconnection support comprising an opening facing the deformable zone of the microstructure a film of the annular zone of the microstructure being in an insulating thermofusible material and coming into contact with a substrate of the support to form a sealing joint around the deformable zone of the microstructure.

41. A The microsystem according to claim 40, wherein a substrate of the support comprises a film formed in a thermofusible insulating material obtained from an electro-initiated reaction, a part of the substrate coming into contact with the film of the annular zone of the microstructure to form a sealing joint around the deformable zone of the microstructure by heat sealing.

42. An electromechanical microstructure comprising:

a first mechanical part formed in a first electrically conductive material, and which comprises (1) a zone deformable in an elastic manner having a thickness value and an exposed surface and (2) a first organic film having a thickness, present on a whole of the exposed surface of the deformable zone,

wherein the first organic film is bonded in a covalent manner to the exposed surface of the deformable zone and formed from an electro-initiated reaction, and

wherein the first electrically conductive material constituting the first mechanical part is a doped semi-conductor, and wherein a doping of type opposite to that of the first material defines an electrode contact at a surface of the first mechanical part outside of the exposed surface.

43. A wafer comprising a series of the electromechanical microstructures according to claim 42, and comprising a first shared electrode electrically connecting all of the electrode pads and wherein a polarity necessary to electro-initiate the organic films corresponds to an open sense of a diode created by the doping in a sense from the electrode contact towards the mechanical part.

44. A wafer comprising:

a series of the electromechanical microstructures comprising,

a first mechanical part formed in a first electrically conductive material, and which comprises (1) a zone deformable in an elastic manner having a thickness value and an exposed surface and (2) a first organic film having a thickness, present on a whole of the exposed surface of the deformable zone,

wherein the first organic film is bonded in a covalent manner to the exposed surface of the deformable zone and formed from an electro-initiated reaction; and

a first shared electrode electrically connecting all of the first mechanical parts of the series of the electromechanical microstructures.