Integrated vertical spiral inductor on semiconductor material

• US 6,611,188 B2
• Filed: 09/03/2002
• Issued: 08/26/2003
• Est. Priority Date: 03/06/2000
• Status: Expired due to Term

• Current Assignee: Chartered Semiconductor Manufacturing Incorporated (GlobalFoundries, Inc.)
• Original Assignee: Chartered Semiconductor Manufacturing Incorporated (GlobalFoundries, Inc.)
• Inventors: Ma, Jiang Guo, Tan, Hai Yeng, Yeo, Kiat Seng, Do, Manh Anh, Chew, Kok Wai Johnny
• Primary Examiner(s): Nguyen, Tuyen T.
• Application Number:
  US10/233,771
• Publication Number:
  US 20030013264A1
• Time in Patent Office: 357 Days
• Field of Search: 336/65, 336/83, 336/192, 336/183, 336/200, 336/206-208, 336/232, 296/021, 296/05
• US Class Current: 336/192
• CPC Class Codes: H01F 17/0013 with stacked layers
• CPC Class Codes: H01F 41/041 Printed circuit coils apparatus or processes for manufacturing printed circuits in general H05K3/00
• CPC Class Codes: H01L 23/5227 Inductive arrangements or effects of, or between, wiring layers other inductive arrangements H01L23/645
• CPC Class Codes: H01L 23/645 Inductive arrangements H01L23/647, H01L23/66 take precedence
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/3011 Impedance

Abstract

A new structure is provided for the creation of an inductor on the surface of a silicon semiconductor substrate. The inductor is of spiral design and perpendicular to the plane of the underlying substrate. Conductor line width can be selected as narrow or wide, ferromagnetic material can be used to fill the spaces between the conductors of the spiral inductor. The spiral inductor of the invention can further by used in series or in series with conventional horizontal inductors.

Claims

1. A structure of a vertical spiral inductor having a height Hc having a direction, having a width Wc having a direction, and having a length Lc having a direction, and a body whereby said body of said spiral conductor is bounded lengthwise and in a plane that is perpendicular to said surface of said substrate by a front surface and a back surface, whereby said vertical spiral conductor can be created on a surface of a silicon semiconductor substrate said surface having a plane, containing:

a base horizontal conductor that is a horizontal conductor that is located closest to said surface of said substrate when compared with all other horizontal conductors;

a section of lower horizontal conductors and a section of upper horizontal conductors overlaying said base horizontal conductor whereby all horizontal conductors including said base horizontal conductor are separated by a space of height Hs in a direction that is perpendicular to said surface of said substrate whereby a plane in which said horizontal conductors are created is parallel to a plane of said surface of said substrate whereby said horizontal conductors can be divided in lower horizontal conductors and upper horizontal conductors;

a first input/output section located between said lower and said upper horizontal conductors containing a horizontal conductor of extended width that serves as one of two input/output connectors to said spiral inductor in addition to containing a point of connect to said lower horizontal conductors;

a second input/output section containing a horizontal conductor that serves as one of two input/output connections to the spiral inductor; and

vertical connecting conductors separated by space Hs whereby a plane of said vertical connecting conductors is perpendicular to said plane of said horizontal conductors whereby said vertical connecting conductors establish electrical contact between horizontal conductors such that a combined configuration of said horizontal conductors and said vertical conductors forms a spiral.

2. The structure of claim 1 wherein each of said horizontal conductors comprises:

a conductor length Cl in said direction Lc and in a plane that is parallel to said surface of said substrate;

conductor sidewalls in a direction of said conductor length and in a plane that is perpendicular to said surface of said substrate henceforth referred to as lengthwise horizontal conductor sidewalls;

a conductor width Cw in a said direction Wc and in a plane that is parallel to said surface of said substrate whereby said conductor width Cw is smaller than said conductor length Cl;

conductor sidewalls in a direction of said conductor width and in a plane that is perpendicular to said surface of said substrate henceforth referred to as widthwise horizontal conductor sidewalls;

a conductor thickness Ch in a plane that is perpendicular to said surface of said substrate;

a conductor upper surface in a plane that is parallel to said surface of said substrate whereby said conductor upper surface has a geometric shape of a rectangle;

a conductor lower surface in a plane that is parallel to said surface of said substrate whereby said conductor lower surface has a geometric shape of a rectangle; and

vertical interconnect surface areas that occupy opposing extremities of either said conductor upper or lower surface of said horizontal conductor in a direction of width of said horizontal conductors whereby said vertical interconnect surface areas are used to establish contact with said vertical connecting conductors.

3. The structure of claim 1 wherein said horizontal conductors contain a multiplicity of horizontal conductors whereby:

all horizontal conductors are of equal width Cw therefrom excluding said first and second input/output conductors;

all horizontal conductors are of equal thickness Ch;

points of intercept of diagonals of said rectangles that form said geometric shape of said upper and lower surface of said horizontal conductors are located on two lines that are perpendicular to a surface of said substrate whereby a first of said two lines applies to horizontal conductors that are located below said first input/output section of said vertical spiral inductor thereby including said base horizontal conductor while a second of said two lines applies to horizontal conductors that are located above said first input/output section of said vertical spiral inductor;

a space separates adjacent horizontal conductors thereby including said base horizontal conductor;

a horizontal conductor that is furthest removed from said surface of said substrate when compared with all other horizontal conductors henceforth referred to as a second input/output horizontal conductor;

a multiplicity of lower level horizontal conductors overlying said base horizontal conductor that are equally spaced between said base horizontal conductor and said first input/output section whereby said length of adjacent horizontal conductors starting with a horizontal conductor that is adjacent to said base horizontal conductor is reduced up to a point of height where said first input/output section is reached;

a first input/output horizontal conductor separated from said lower level conductors by a space of height Hs and overlying said lower level horizontal conductors which is that horizontal conductor that has a smallest horizontal conductor length when compared with all other horizontal conductors whereby the width of said innermost horizontal conductor is extended said extension to serve as a first input/output connection for said vertical spiral inductor said first input/output horizontal conductor being connected to said lower level horizontal conductors;

a multiplicity of upper level horizontal conductors overlying said first input/output section that are equally spaced between said first input/output section and said second input/output section whereby said length of adjacent horizontal conductors starting with a horizontal conductor that is adjacent to said first input/output section is increased up to a point of height where said second input/output section is reached; and

a second input/output horizontal conductor overlying said upper level horizontal conductors and separated from said upper level horizontal conductors by a space of height Hs which is that horizontal conductor that has a largest horizontal conductor length when compared with all other horizontal conductors whereby a dimension of width of said innermost horizontal conductor is extended said extension to serve as a second input/output connection for said vertical spiral inductor.

4. The structure of claim 1 wherein each conductor of said vertical connecting conductors comprises:

a conductor height in said direction Hc in a plane that is perpendicular to said surface of said substrate;

a conductor width of Wc in said direction Wc in a plane that is parallel to said surface of said substrate;

a conductor thickness of Hb in said direction Lc in a plane that is parallel to said surface of said substrate;

a conductor cross section in a plane that is parallel to said surface of said substrate that has the shape of a geometric rectangle;

a conductor upper surface in a plane that is perpendicular to said surface of said substrate;

a conductor lower surface in a plane that is perpendicular to said surface of said substrate;

two conductor sidewalls that are parallel with the length of said a vertical connecting conductor henceforth referred to as lengthwise vertical conductor sidewalls; and

two conductor sidewalls that are parallel with the width of said a vertical connecting conductor henceforth referred to as widthwise vertical conductor sidewalls.

5. The structure of claim 1 wherein said vertical conductors contain a multiplicity of vertical conductors whereby:

the upper surface and lower surface of each vertical conductor has a geometric shape of a rectangle whereby opposing corners of each of said rectangles can be connected by two lines that form diagonals of said rectangles whereby said diagonals have a point of intercept whereby said points of intercept are located on a line that is parallel to said surface of said substrate and further is in a direction that is parallel with said conductor lengthwise horizontal conductor sidewalls;

adjacent vertical conductors are separated by a space;

two vertical conductors henceforth referred to as outer vertical conductors that are connected to said base horizontal conductor whereby said connections are established between said one of two widthwise vertical conductor sidewalls of each of said outer vertical conductors and said vertical interconnect surface areas on said upper surface of said base horizontal conductor;

a multiplicity of vertical conductors that are spaced between said outer vertical conductors whereby said height of adjacent vertical conductors is adjusted such that the combined structure of horizontal and vertical conductors forms a spiral said spiral to be apparent in a cross section of said body of said spiral inductor with a plane that is perpendicular to said surface of said substrate that furthermore is parallel with said lengthwise conductor sidewalls of said horizontal conductors.

6. The structure of claim 1 wherein said conductor width is between about 4 and 10 times said conductor thickness.

7. The structure of claim 6 whereby said space between said horizontal conductors and said space between said vertical interconnect conductors is filled with one or more layers of a dielectric.

8. The structure of claim 6 whereby said space between said horizontal conductors and said space between said vertical interconnect conductors is filled with one or more layers of a ferromagnetic material.

9. The structure of claim 6 whereby two spiral inductors are connected in series.

10. The structure of claim 1 wherein said conductor width is between about 10 and 50 times the conductor thickness.

11. The structure of claim 10 whereby said space between said horizontal conductors and said space between said vertical interconnect conductors is filled with one or more layers of a dielectric.

12. The structure of claim 10 whereby said space between said horizontal conductors and said space between said vertical interconnect conductors is filled with one or more layers of a ferromagnetic material.

13. The structure of claim 10 whereby two spiral inductors are connected in series.

14. The structure of claim 1 wherein said second input/output section that contains one of two input/output connections to the spiral inductor comprises:

a main conductor having all attributes of said horizontal conductors;

a first and a second vertical interconnect surface area that occupy opposing extremities of either said upper or lower surfaces of said main conductor in a direction of said widthwise horizontal conductor sidewalls whereby said first vertical interconnect surface area is used for establishing contact with the outer vertical connecting conductors of which not both widthwise vertical sidewalls are in contact with horizontal conductors; and

an extension that is attached to said rectangle of said main conductor having two sidewalls in a plane that is perpendicular to the surface of said substrate whereby one of said two sidewalls is an extension of that widthwise horizontal sidewall of said main conductor that has not previously been connected to a vertical conductor whereby said extension preferably has a geometric shape of a rectangle.

15. The structure of claim 1 wherein each of said horizontal conductors thereby including said first and said second input/output sections has a geometric shape of a rectangle whereby opposing corners of each of said rectangles can be connected with two lines that form diagonals of said rectangles whereby said diagonals have a point of intercept whereby said points of intercept for said closest spaced horizontal conductor and said furthest spaced horizontal conductors are located on a line that is perpendicular to said surface of said substrate and forms a start and an end point of a line that interconnects said points of intercept of said diagonals of said horizontal conductors whereby said line is located in a plane that is perpendicular to said surface of said substrate said plane furthermore being parallel with said lengthwise sidewalls of said horizontal conductors whereby said line is non-linear thereby creating a spiral structure whereby spirals of said spiral inductor protrude from said body of said spiral inductor whereby said first and second input sections are further created as input/output connectors to said vertical spiral conductor after said protrusion of said spiral inductor has been determined whereby said body of said spiral conductor is no longer bounded lengthwise and in a plane that is perpendicular to said surface of said substrate by a front surface and a back surface of said vertical spiral inductor.

16. The structure of claim 15 wherein said line that interconnects said points of intercept of said diagonals of said horizontal conductors is a parabola.

17. The structure of claim 15 wherein said conductor width is between about 4 and 10 times said conductor thickness.

18. The structure of claim 15 whereby said space between said horizontal conductors and said space between said vertical interconnect conductors is filled with one or more layers of a dielectric.

19. The structure of claim 15 whereby said space between said horizontal conductors and said space between said vertical interconnect conductors is filled with one or more layers of a ferromagnetic material.

20. The structure of claim 1 wherein said conductor width is between about 10 and 50 times the conductor thickness.

21. The structure of claim 20 whereby said space between said horizontal conductors and said space between said vertical interconnect conductors is filled with one or more layers of a dielectric.

22. The structure of claim 20 whereby said space between said horizontal conductors and said space between said vertical interconnect conductors is filled with one or more layers of a ferromagnetic material.

23. The structure of claim 1 whereby said vertical spiral inductor is connected in series with a conventional horizontal inductor whereby said horizontal inductor overlays said vertical inductor.

24. The structure of claim 23 wherein space between spirals of said horizontal conductors and space between spirals of said vertical inductor is filled with one or more layers of dielectric material.

25. The structure of claim 23 wherein space between spirals of said horizontal conductors and space between spirals of said vertical inductor is filled with one or more layers of ferromagnetic material.

26. The structure of claim 1 whereby said vertical spiral inductor is connected in series with a conventional horizontal inductor whereby a plane of an upper surface of said horizontal inductor coincides with a plane of an upper surface of said vertical inductor.

27. The structure of claim 26 wherein space between spirals of said horizontal conductors and space between spirals of said vertical inductor is filled with one or more layers of dielectric material.

28. The structure of claim 26 wherein space between spirals of said horizontal conductors and space between spirals of said vertical inductor is filled with one or more layers of ferromagnetic material.

29. A structure of a vertical spiral inductor having a body that can be created on the surface of a silicon semiconductor substrate, containing:

horizontal conductors separated by space having a horizontal conductor width and thickness whereby said horizontal conductors are parallel with said surface of said substrate and that are separated by space;

vertical connecting conductors separated by space having a vertical connecting conductor width and thickness whereby said vertical connecting conductors are perpendicular to said horizontal conductors and are separated by space whereby said width of said vertical connecting conductor equals said width of said horizontal conductors whereby furthermore a direction of width of said vertical connecting conductors coincides with a direction of width of said horizontal conductors;

areas of interconnect between said horizontal conductors and said vertical conductors creating a structure such that a cross section of said body of said vertical spiral inductor taken in a plane that is perpendicular to said surface of said substrate and perpendicular to said direction of width of said horizontal conductors has a geometric shape of a spiral;

an extension provided to an innermost horizontal conductor that protrudes from the body of said vertical spiral inductor and that serves as input/output connection to said spiral inductor; and

a horizontal upper conductor that makes contact with a vertical conductor of maximum longitudinal dimension that has furthermore been provided with a conductor that is an extension of said horizontal upper conductor in a direction of width of said horizontal conductor whereby said extension has a surface with a geometric shape of a rectangle whereby said extension is provided on that side of said horizontal upper conductor that is not connected to a vertical conductor said extension to serve as an input/output connection.

30. The structure of claim 29 whereby said horizontal conductor width and said vertical connecting conductor width are between about 6 and 10 times said horizontal and vertical conductor thickness.

31. The structure of claim 30 whereby said space between said horizontal conductors and said vertical connecting conductors is filled with one or more layers of dielectric material.

32. The structure of claim 30 whereby said space between said horizontal conductors and said vertical connecting conductors is filled with one or more layers of ferromagnetic material.

33. The structure of claim 30 whereby two or more of said vertical spiral inductors are connected in series.

34. The structure of claim 30 whereby said vertical spiral inductor is connected in series with a conventional horizontal spiral inductor whereby said horizontal spiral inductor overlays said vertical spiral inductor.

35. The structure of claim 30 whereby said vertical spiral inductor is connected in series with a conventional horizontal spiral inductor whereby an upper surface of said horizontal spiral inductor is in a plane of an upper surface of said vertical spiral inductor.

36. The structure of claim 30 whereby said horizontal conductor width and said vertical connecting conductor width are between about 10 and 50 times said horizontal and vertical conductor thickness.

37. The structure of claim 36 whereby said space between said horizontal conductors and said vertical connecting conductors is filled with one or more layers of dielectric material.

38. The structure of claim 36 whereby said space between said horizontal conductors and said vertical connecting conductors is filled with one or more layers of ferromagnetic material.

39. The structure of claim 36 whereby two or more of said vertical spiral inductors are connected in series.

40. The structure of claim 36 whereby said vertical spiral inductor is connected in series with a conventional horizontal spiral inductor whereby said horizontal spiral inductor overlays said vertical spiral inductor.

41. The structure of claim 36 whereby said vertical spiral inductor is connected in series with a conventional horizontal spiral inductor whereby an upper surface of said horizontal spiral inductor is in a plane of an upper surface of said vertical spiral inductor.

42. The structure of claim 36 whereby said horizontal and said vertical conductors are protruding from the body of said vertical spiral inductor whereby said protrusion is most prominent and centered between a horizontal conductor of said spiral inductor that is closest to said surface of said substrate and a horizontal conductor that is furthest removed from said surface of said substrate with said protrusion further diminishing from a point of maximum protrusion when proceeding in a direction of outermost vertical interconnecting conductors of said vertical spiral inductor.

43. The structure of claim 42 whereby said horizontal conductor width and said vertical connecting conductor width are between about 6 and 10 times said horizontal and vertical conductor thickness.

44. The structure of claim 42 whereby said space between said horizontal conductors and said vertical connecting conductors is filled with one or more layers of dielectric material.

45. The structure of claim 42 whereby said space between said horizontal conductors and said vertical connecting conductors is filled with one or more layers of ferromagnetic material.

46. The structure of claim 42 whereby said horizontal conductor width and said vertical connecting conductor width are between about 10 and 50 times said horizontal and vertical conductor thickness.

47. The structure of claim 46 whereby said space between said horizontal conductors and said vertical connecting conductors is filled with one or more layers of dielectric material.

48. The structure of claim 46 whereby said space between said horizontal conductors and said vertical connecting conductors is filled with one or more layers of ferromagnetic material.