Methods and apparatus for fabricating capacitor structures with a terminal shield

Patent metadata

Field	Value
Publication number	US-9331026-B1
Application number	US-201414274499-A
Country	US
Kind code	B1
Filing date	May 9, 2014
Priority date	May 9, 2014
Publication date	May 3, 2016
Grant date	May 3, 2016

Abstract

A capacitor structure having a complete terminal shield is provided. The capacitor structure may include a first conductive segment with a first set of conductive fingers and a second segment structure with a second set of conductive fingers. The second set of conductive fingers may be spatially interleaved with the first set of conductive fingers in the first conductive structure. The first conductive segment may receive a first voltage, whereas the second conductive segment may receive a second voltage that is different than the first voltage. The capacitor structure further includes a conductive shielding structure that is connected to the first conductive segment. The conductive shielding structure may laterally surround the second conductive segment from at least three sides. An additional conductive shielding structure that connects to the first and second conductive segments is formed directly above the first and second conductive segments.

First claim

What is claimed is:

1. A capacitor structure having first and second terminals, comprising:
a substrate;
a dielectric stack formed over the substrate;
a first conductive segment that is formed in a first layer of the dielectric stack, wherein the first conductive segment is connected to the first terminal of the capacitor structure;
a second conductive segment that is formed directly above the first conductive segment in a second layer of the dielectric stack, wherein the first and second layers are directly adjacent layers in the dielectric stack, and wherein the second conductive segment is connected to the first terminal of the capacitor structure;
a third conductive segment that is formed in the second layer of the dielectric stack, wherein the third conductive segment is coupled to the second terminal of the capacitor structure; and
a conductive shielding structure that is formed directly above the third conductive segment in a third layer of the dielectric stack, wherein the conductive shielding structure is coupled to the second conductive segment.

2. The capacitor structure defined in claim 1 , wherein the first terminal of the capacitor structure is coupled to ground.

3. The capacitor structure defined in claim 1 , further comprising:
a conductive shielding segment that is formed in the second layer of the dielectric stack, wherein the conductive shielding segment is perpendicular to the second and third conductive segments, and wherein the conductive shielding segment is coupled the second conductive segment.

4. The capacitor structure defined in claim 1 wherein the third conductive segment is shorter than the second conductive segment.

5. The capacitor structure defined in claim 1 wherein the first conductive segment is electrically coupled to the second conductive segment through conductive vias.

6. The capacitor structure defined in claim 1 , wherein the conductive shielding structure is electrically coupled to the second conductive segment through conductive vias.

7. The capacitor structure defined in claim 2 further comprising:
a conductive structure that includes the first conductive segment, wherein the conductive structure is formed directly below the second and third conductive segments in the first layer of the dielectric stack.

8. An integrated circuit, comprising:
a semiconductor substrate; and
a plurality of dielectric layers formed on the semiconductor substrate, wherein a layer in the plurality of the dielectric layers comprises:
a first conductive structure with a first plurality of conductive fingers;
a second conductive structure with a second plurality of conductive fingers that is spatially interleaved with the first plurality of conductive fingers, wherein the first conductive structure and the second conductive structure form a capacitor structure; and
a conductive shielding structure that connects to the first conductive structure and that laterally surrounds the second conductive structure from at least three sides.

9. The integrated circuit defined in claim 8 wherein another layer in the plurality of the dielectric layers comprises:
an additional conductive shielding structure formed directly above the first and second conductive structures.

10. The integrated circuit defined in claim 9 , wherein the additional conductive shielding structure comprises:
a third conductive structure with a third plurality of conductive fingers; and
a conductive segment that is surrounded by the third conductive structure, wherein the conductive segment is parallel with the third plurality of conductive fingers.

11. The integrated circuit defined in claim 10 , wherein the first and third conductive structures are coupled to a first terminal of the capacitor structure, and wherein the second conductive structure and the conductive segment are coupled to a second terminal of the capacitor structure.

12. The integrated circuit defined in claim 8 wherein another layer in the plurality of the dielectric layers comprises:
an additional conductive shielding structure that is formed in the another layer in the plurality of dielectric layers, wherein the another layer in the dielectric stack is directly below the layer in the dielectric stack.

13. The integrated circuit defined in claim 12 , wherein the first conductive structure and the additional conductive shielding structure receive a first voltage, and wherein the second conductive structure receives a second voltage that is different than the first voltage.

14. The integrated circuit defined in claim 12 , wherein the additional conductive shielding structure is electrically coupled to the first conductive structure through conductive via structures.

15. A method of fabricating a capacitor structure over a substrate, comprising:
forming a dielectric stack on the substrate;
forming a first conductive structure in a first layer of the dielectric stack;
forming a second conductive structure with a first plurality of conductive fingers in a second layer of the dielectric stack, wherein the second layer of the dielectric stack is adjacent to and above the first layer in the dielectric stack;
forming a third conductive structure with a second plurality of conductive fingers in the second layer of the dielectric stack, wherein the second plurality of conductive fingers is spatially interleaved with the first plurality of conductive fingers; and
forming a conductive shielding structure that is connected to the first and second conductive structures and that laterally surrounds the third conductive structure from at least three sides.

16. The method defined in claim 15 , further comprising:
forming an additional conductive shielding structure above the second and third conductive structures in a third layer of the dielectric stack.

17. The method defined in claim 16 , wherein forming the additional conductive shielding structure comprising:
forming a fourth conductive structure with a third plurality of conductive fingers, wherein each conductive finger in the third plurality of conductive fingers extends in parallel to each other; and
forming a conductive segment that is surrounded laterally by the third conductive structure in the third layer of the dielectric stack, wherein the conductive segment is adjacent to the third plurality of conductive fingers.

18. The method defined in claim 17 further comprising:
coupling the first and second conductive structures and the fourth conductive structure to a first voltage; and
coupling the third conductive structure and the conductive segment to a second voltage that is different than the first voltage.

19. The method defined in claim 17 , further comprising:
aligning the conductive segment above the third conductive structure so that the conductive segment is in electrical contact with the third conductive structure.

20. The method defined in claim 15 wherein forming the first conductive structure comprises forming a conductive solid layer that is attached to a ground terminal in the substrate.

Assignees

• Altera Corp

Inventors

• Watt Jeffrey T
• Chen Shuxian

Classifications

• H10W20/496

  Capacitor integral with wiring layers · CPC title

• H10W20/423

  Shielding layers · CPC title

• H10W42/00 Primary

  Arrangements for protection of devices (arrangements for thermal protection H10W40/00) · CPC title

• H10D1/716

  having vertical extensions · CPC title

• H10D1/714 Primary

  having horizontal extensions · CPC title