Integrated vertical spiral inductor on semiconductor material

• US 6,800,533 B1
• Filed: 03/06/2000
• Issued: 10/05/2004
• Est. Priority Date: 03/06/2000
• Status: Expired due to Term

• Current Assignee: Chartered Semiconductor Manufacturing Incorporated (Mamoura Diversified Global Holding PJSC)
• Original Assignee: Chartered Semiconductor Manufacturing Incorporated (Mamoura Diversified Global Holding PJSC)
• Inventors: Yeo, Kiat Seng, Do, Manh Anh, Chew, Kok Wai Johnny, Tan, Hai Peng, Ma, Jian Guo
• Primary Examiner(s): POTTER, ROY KARL
• Application Number:
  US09/519,427
• Time in Patent Office: 1,674 Days
• Field of Search: 257/531, 257/752, 438/329, 438/24, 438/57, 438/381, 336/222-223, 336/232, 333/140
• US Class Current: 438/381
• 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 method of creating a vertical spiral inductor containing horizontal and vertical conductors of a width Wc, said width having a direction separated by spacing further containing a first and a second input/output connector, said vertical spiral inductor containing a body that is bounded by a base horizontal conductor, two outer vertical conductors and said second input/output connector, whereby said vertical spiral inductor can be viewed in a direction of width that is parallel with said surface of said substrate resulting in a horizontal view one of said inductor, comprising the steps of:

providing a semiconductors substrate, said substrate having a surface;

depositing a base layer of dielectric having a surface over said surface of said substrate;

creating a base section of said vertical spiral inductor having a surface further having a height Hb and a width Wc, said base section being created on said surface of said base layer of dielectric;

creating a lower section of said vertical spiral inductor having a height Hl, said lower section being created overlying said surface of said base section;

creating a first input/output connector section having a height Hfio further having a surface, said first input/output section being created on said surface of said lower section;

creating an upper section of said vertical spiral inductor having a surface further having a height Hu, said upper section being created on said surface of said first input/output section; and

creating a second input/output connector section having a surface further having a height Hsio, said second input/output section being created on said surface of said upper section.

2. The method of claim 1 wherein said creating a base section of said vertical spiral inductor comprises the steps of:

depositing a first layer of dielectric having a surface over said surface of said base layer of dielectric;

patterning and etching said first layer of dielectric thereby creating a trench in said first layer of dielectric for a base horizontal conductor;

depositing a first layer of metal over said surface of said first layer of dielectric thereby filling said trench;

planarizing said first layer of metal down to said surface of said first layer of dielectric thereby creating a base horizontal conductor said base horizontal conductor having a surface, a length, a height, a width, a thickness and two surface areas that are a subset of said surface of said base horizontal conductor and that serve as vertical conductor contact areas that occupy opposite extremities of said surface of said base horizontal conductor in a direction of width over the width of said base horizontal conductor and in a direction of length that equals said thickness of said horizontal conductor whereby said vertical conductor contact areas can be divided into a right most vertical contact area and a left most vertical contact area said division being derived at by facing said vertical spiral in a direction of width of said vertical spiral in a plane that is parallel to said plane of said substrate.

3. The method of claim 1 wherein said creating a lower section of said vertical spiral inductor comprises the steps of:

depositing a second layer of dielectric over said base section of said vertical spiral thereby including said planarized surface of said base horizontal conductor whereby a thickness of said second layer of dielectric equals said spacing between said horizontal and said vertical conductors;

patterning and etching said second layer of dielectric thereby creating openings in said second layer of dielectric that align with said vertical contact areas in said base horizontal conductor;

depositing a third layer of dielectric over said second layer of dielectric;

patterning and etching said third layer of dielectric thereby creating a trench in said third layer of dielectric that aligns with said base horizontal conductor said trench having a length whereby said length equals said length of said base horizontal conductor minus two times the combined value of said thickness of said vertical conductors and said gap between said vertical conductors in addition to creating openings in said third layer of dielectric that align with said vertical contact areas in said base horizontal conductor two vertical conductor contact areas when facing said vertical spiral is a direction of width of said horizontal conductors;

depositing a layer of metal over said surface of said third layer of dielectric thereby including said trench and said openings that have been created in said second and said third layer of dielectric;

planarizing said layer of metal that has been deposited over said surface of said third dielectric thereby creating partial vertical conductors overlaying said vertical conductor contact areas further creating a first horizontal conductor said first horizontal conductor having a height Hb further having a width Wc further containing two upper surface areas that serve as vertical contact areas that occupy opposite extremities of said surface of said first horizontal conductor in a direction of width over the width of said horizontal conductor and in a direction of length that equals said thickness of said horizontal conductor whereby said vertical conductor contact areas can be divided into a right most vertical contact area and a left most vertical contact area said division being derived at by facing said vertical spiral in a direction of width of said vertical spiral in a plane that is parallel to said plane of said substrate; and

repeating previous steps starting with depositing a second layer of dielectric up through and including said planarizing said layer of metal that has been deposited over said surface of said third dielectric whereby for each repetition an additional horizontal conductor to a preceding horizontal conductor is created that aligns with said preceding horizontal conductor of height Hb and width Wc whereby a length for each additional horizontal conductor equals a length of said preceding horizontal conductor minus two times the combined value of said thickness of said vertical conductor and said gap between said vertical conductors while furthermore for each repetition two additional extensions are created in said second and third layer of dielectric that align with vertical conductor contact areas of underlying horizontal conductors said repetition being continued until the combined thickness of said second and third layer of dielectric equals said lower section height Hl.

4. The method of claim 1 wherein said creating said first input/output connector section comprises the steps of:

depositing a fourth layer of dielectric having a surface over said surface of said lower section;

patterning and etching said fourth layer of dielectric thereby creating an opening in aid fourth layer of dielectric that aligns with a rightmost vertical conductor contact area in a horizontal conductor that is exposed in said surface of said lower section of said vertical spiral conductor whereby said rightmost vertical conductor contact area is the rightmost of said two vertical conductor contact areas when facing said vertical spiral is a direction of width of said horizontal conductors where by said rightmost opening is the opening that aligns with said first input/output connector;

depositing a fifth layer of dielectric having a surface over said surface of said fourth layer of dielectric;

patterning and etching said fifth layer of dielectric thereby creating a trench in said fifth layer of dielectric in addition to creating openings that align with said underlying vertical contact areas of underlying horizontal conductors whereby said trench aligns and makes contact with said right most opening that has been created in said fourth layer of dielectric whereby furthermore said trench extends in said dimension of width of said horizontal conductors by a considerable amount;

depositing a layer of metal over said surface of said fifth layer of dielectric thereby including said trench and said openings that have been created in said fifth layer of dielectric; and

planarizing said layer of metal that has been deposited over said surface of said fifth dielectric thereby creating a first input/output connector.

5. The method of claim 1 wherein said creating an upper section of said vertical spiral inductor is:

depositing a sixth layer of dielectric having a surface and a seventh layer of dielectric having a surface over said surface of said first input/output section of said vertical spiral inductor;

forming a dual damascene pattern in said sixth and seventh layer of dielectric said dual damascene pattern containing a left most via and a right most via and a trench connecting said left most via with said right most via whereby said trench of said dual damascene pattern is designed to contain a horizontal conductor whereby said vias align with innermost partially completed vertical conductors whereby furthermore said trench of said dual damascene pattern is bounded by said vias;

depositing a layer of metal over said surface of said seventh layer of dielectric thereby including said trench and said openings that have been created in said sixth and seventh layers of dielectric;

planarizing said layer of metal that has been deposited over said surface of said seventh layer of dielectric thereby creating a first horizontal conductor of said upper section of said vertical spiral inductor;

repeating said steps of depositing a sixth and seventh layer of dielectric thereby creating layers of horizontal conductors that align with said first input/output connector further having a length whereby said horizontal conductors are progressively further removed from said surface of said substrate whereby said length of said trench of said dual damascene pattern is adjusted such that the thereby created vias step wise expand from said innermost partially completed vertical conductors and further connect said horizontal conductors in said upper section of said vertical spiral with said horizontal conductor in said lower section in said vertical spiral in a spiral pattern said repetition being continued to the point where the total thickness of the aggregate deposits of sixth and seventh layer of dielectric equals said Hu at which point one vertical conductor remains unconnected at a lengthwise extremity of this conductor that is furthest removed from said surface of said substrate whereby said unconnected vertical conductor aligns with said left most vertical conductor connect area in said surface of said base horizontal conductor.

6. The method of claim 1 wherein said creating a second input/output connector section comprises the steps of:

depositing an eighth and ninth layer of dielectric having a surface over said surface of said upper section of said vertical spiral;

creating and etching a dual damascene pattern in said eight and ninth layer of dielectric whereby a via of said dual damascene pattern aligns with said unconnected remaining vertical conductor while furthermore a trench of said dual damascene pattern extends in said dimension of width of said horizontal conductors by a considerable amount;

depositing a layer of metal over said surface of said ninth layer of dielectric thereby including said via that has been created in said eighth layer of dielectric and said trench that has been created in said ninth layer of dielectric;

planarizing said layer of metal down to said surface of said ninth layer of dielectric; and

depositing a layer of passivation material over said surface of said ninth layer of dielectric thereby providing environmental protection for said vertical spiral.

7. The method of claim 1 wherein each of said horizontal conductors comprises:

a conductor length 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 in a plane that is parallel to said surface of said substrate whereby said conductor width is smaller than said conductor length;

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 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 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;

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 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; 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 for establishing contact with said vertical connecting conductors.

8. The method of claim 1 wherein each conductor of said vertical connecting conductors comprises:

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

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

a conductor thickness 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.

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

10. The method of claim 1 wherein each step of patterning and etching to create openings and trenches in each of said layers of dielectric that are used in said vertical spiral inductor is preceded by the steps of:

patterning and etching said layer of dielectric whereby said patterning uses the mirror image pattern of a pattern that is used for patterning and etching to create openings and trenches in each of said layers of dielectric for said horizontal and vertical conductors whereby said mirror image pattern is bounded by said base horizontal conductor, said two outer vertical conductors and said second input/output connector, hereby creating openings and trenches in said layer of dielectric that are within said bounds of said vertical spiral and that are mirror image openings and trenches to said horizontal and vertical conductors;

filling said mirror image openings and trenches with a ferromagnetic material; and

planarizing said ferromagnetic material.

11. The structure of claim 1 whereby two spiral inductors are connected in series.

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

13. The method of claim 1 wherein each of said horizontal conductors thereby including said first and said second input/output connectors 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 as line that is perpendicular to said surface of said substrate and form 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.

14. The method of claim 13 wherein said conductor width is between about 4 and 10 times said conductor thickness.

15. The method of claim 13 wherein each step of patterning and etching to create openings and trenches in each of said layers of dielectric that are used in said vertical spiral inductor is preceded by the steps of:

patterning and etching said layer of dielectric whereby said patterning uses the mirror image pattern of a pattern that is used patterning and etching to create openings and trenches in each of said layers of dielectric thereby creating mirror image openings and trenches;

filling said mirror image openings and trenches with a ferromagnetic material; and

planarizing said ferromagnetic material.

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

17. The structure of claim 13 wherein said conductor width is between about 10 and 50 times the conductor thickness.

18. The method of claim 17 wherein each step of patterning and etching to create openings and trenches in each of said layers of dielectric that are used in said vertical spiral inductor is preceded by the steps of:

patterning and etching said layer of dielectric whereby said patterning uses the mirror image pattern of a pattern that is used patterning and etching to create openings and trenches in each of said layers of dielectric thereby creating mirror image openings and trenches;

filling said mirror image openings and trenches with a ferromagnetic material; and

planarizing said ferromagnetic material.

19. The structure of claim 17 whereby two spiral inductors are connected in series.

20. The method of claim 1 wherein said creating said first input/output connector section comprises the steps of:

depositing a fourth layer of dielectric having a surface over said surface of said lower section;

patterning and etching said fourth layer of dielectric thereby creating an opening in aid fourth layer of dielectric that aligns with a leftmost vertical conductor contact area in a horizontal conductor that is exposed in said surface of said lower section of said vertical conductor whereby said leftmost vertical conductor contact area is the leftmost of said two vertical conductor contact areas when facing said vertical spiral coil is a direction of width of said horizontal conductors whereby said leftmost opening is the opening that aligns with said first input/output connector;

depositing a fifth layer of dielectric having a surface over said surface of said fourth layer of dielectric;

patterning and etching said fifth layer of dielectric thereby creating a trench in said fifth layer of dielectric in addition to creating openings that align with said underlying vertical contact areas of underlying horizontal conductors whereby said trench aligns and makes contact with said leftmost opening that has been created in said fourth layer of dielectric whereby furthermore said trench extends in said dimension of width of said horizontal conductors by a considerable amount;

depositing a layer of metal over said surface of said fifth layer of dielectric thereby including said trench and said openings that have been created in said fifth layer of dielectric; and

planarizing said layer of metal that has been deposited over said surface of said fifth dielectric thereby creating a first input/output connector.

21. The method of claim 1 wherein said horizontal view one of said vertical spiral inductor shows said spiral of said vertical spiral inductor whereby said spiral starts at said first input/output connector and further continues by following interconnected vertical and horizontal conductors of said vertical spiral inductor in a clock-wise direction.

22. The method of claim 1 wherein said horizontal view one of said vertical spiral inductor shows said spiral of said vertical spiral inductor whereby said spiral starts at said first input/output connector and further continues by following interconnected vertical and horizontal conductors of said vertical spiral inductor in a counter clock-wise direction.

23. A method of creating a vertical spiral inductor containing horizontal and vertical conductors of a width Wc, said width having a direction separated by spacing further containing a first and a second input/output connector, said vertical spiral inductor containing a body that is bounded by a base horizontal conductor, two outer vertical conductors and said second input/output connector, whereby said vertical spiral inductor can be viewed in a direction of width that is parallel with said surface of said substrate resulting in a horizontal view one of said inductor, comprising the steps of:

providing a semiconductors substrate, said substrate having a surface;

creating a base section of said vertical spiral inductor having a surface further having a height Hb and a width Wc, said base section being created on said surface of said substrate;

creating a lower section of said vertical spiral inductor having a height Hl, said lower section being created overlying said surface of said base section;

creating a first input/output connector section having a height Hfio further having a surface, said first input/output section being created on said surface of said lower section;

creating an upper section of said vertical spiral inductor having a surface further having a height Hu, said upper section being created on said surface of said first input/output section; and

creating a second input/output connector section having a surface further having a height Hsio, said second input/output section being created on said surface of said upper section.