Chip with a vertical contact structure

• US 7,939,946 B2
• Filed: 08/27/2007
• Issued: 05/10/2011
• Est. Priority Date: 08/25/2006
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Sommer, Michael
• Primary Examiner(s): Smith; Bradley K
• Assistant Examiner(s): Payen; Marvin
• Application Number:
  US11/845,338
• Publication Number:
  US 20080048341A1
• Time in Patent Office: 1,352 Days
• Field of Search: 257/773, 257/776, 257/E23.01
• US Class Current: 257/776
• CPC Class Codes: H01L 23/522 including external interconnections consisting of a multilayer structure of conductive and insulating layers inseparably formed on the semiconductor body
• CPC Class Codes: H01L 23/5226 Via connections in a multilevel interconnection structure
• CPC Class Codes: H01L 23/573 using passive means
• CPC Class Codes: H01L 23/585 comprising conductive layers or plates or strips or rods or rings H01L23/60, H01L23/62, H01L23/64, 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

Abstract

A chip with a chip plane includes a functional area, a contact structure vertical with respect to the chip plane for connecting the functional area, which includes a conductive material, which has a predetermined length, and a vertical dummy-contact structure, which extends vertically into the functional area and which has an electrically conductive material and an insulation layer, the insulation layer being formed so that a current flow from an upper end of the dummy-contact structure to the functional area is prevented.

Claims

1. A chip with a chip plane, comprising:

a functional area comprising;

a first active area and a second active area, which is spaced from the first active area;

a first conductive trace, which crosses the first and second active areas, wherein a first insulating layer is arranged between the first active area or the second active area and the first conductive trace; and

a second conductive trace, which is arranged above the first conductive trace, wherein a second insulating layer is arranged between the second conductive trace and the first conductive trace;

a plurality of contact structures vertical with respect to the chip plane for contacting the first active area, the second active area, the first conductive trace or the second conductive trace, wherein the vertical contact structures include a conductive material; and

a vertical dummy-contact structure, which extends vertically into the functional area to the first active area, the second active area, the first conductive trace or the second conductive trace, and which comprises an electrically conductive material and an insulation layer, the insulation layer being formed so that a current flow from an upper end of the dummy-contact structure to the functional area is prevented;

wherein the vertical contact structures comprise

a first vertical contact structure extending up to the first conductive trace, being spaced from the second conductive trace and representing a gate contact of a transistor implemented by the functional area, and a second vertical contact structure extending up to the first or second active area, being spaced from the first contact structure and the first conductive trace and representing a source/drain contact of the transistor, and a third vertical contact structure extending up to the first or second active area, being spaced from the first contact structure and the first conductive trace and representing a further source/drain contact of the transistor;

wherein the dummy-contact structures comprise

a first dummy-contact structure extending up to one of the first conductive trace and the second conductive trace and being spaced from the other of the first conductive trace and the second conductive trace, and a second dummy-contact structure extending up to the first active area or the second active area.

2. The chip according to claim 1, wherein the dummy-contact structure comprises:

a first area of the conductive material, which is connected in a conductive way to the functional area, and a second area of the conductive material, which is arranged on the insulation layer and is electrically insulated from the first area by the insulation layer.

3. The chip according to claim 1, wherein the insulation layer of the dummy-contact structure is arranged on the functional area and covers at least partly the functional area, and the conductive material is arranged on a side of the insulation layer facing away from the functional area.

4. The chip according to claim 1, wherein the conductive material is arranged at the upper end of the vertical dummy-contact structure.

5. The chip according to claim 1, wherein the conductive material of the vertical dummy-contact structure is identical to the conductive material of the vertical contact structure.

6. The chip according to claim 1, wherein a vertical or horizontal dimension of the vertical dummy-contact structure is, to within a tolerance of 10%, equal to a vertical or horizontal dimension of the vertical contact structures.

7. The chip according to claim 1, wherein a thickness of the insulation layer is smaller than 50% of the length of the vertical contact structures.

8. The chip according to claim 1, wherein the conductive material of each of the vertical dummy-contact structure and the contact structures is arranged in a hole of the chip, a root of the area of the hole being smaller than the length of the vertical contact structures.

9. The chip according to claim 1, wherein the insulation layer of the dummy-contact structure is arranged between two metal layers surrounding the dummy-contact structure, the vertical dummy-contact structure being arranged, to within a predetermined tolerance from 80°

to 100°

, perpendicularly to one of the two metal layers.

10. The chip according to claim 1, wherein the vertical dummy-contact structure comprises a lower end facing away from the upper end, and a distance between the upper end and the lower end is, to within a 10% tolerance, identical to the length of the vertical contact structures.

11. The chip according to claim 1, wherein the vertical dummy-contact structure is arranged substantially parallel to the vertical contact structures for contacting the functional area, and the vertical contact structures comprise a lower end facing toward the functional area and an upper end facing away from the functional area, wherein an upper contact structure end plane, in which the upper end of the contact structure is located and which is parallel to the chip plane, is spaced by less than 10% of the predetermined length from an upper dummy-contact structure end plane, in which the upper end of the dummy-contact structure is located and which is also parallel to the chip plane.

12. The chip according to claim 1, further comprising a third dummy-contact structure, which is spaced from the first dummy-contact structure and the one of the first conductive trace or the second conductive trace and extends up to the other of the first conductive trace or the second conductive trace.

13. The chip according to claim 1, wherein the first conductive trace is subdivided into a first sub-area, a second sub-area and a third sub-area;

wherein the second sub-area of the first conductive trace overlaps, in a plan view in a direction vertical to the chip plane, with the second conductive trace, and the first sub-area does not overlap, at a first end first of the conductive trace, in the plan view, with the second conductive trace, and the third sub-area of the first conductive trace does not overlap, in the plan view, with the second conductive trace, and extends up to the first end of the first conductive trace facing away from the second end of the first conductive trace;

wherein the first vertical contact structure extends up to the third sub-area of the first conductive trace and the first vertical dummy-contact structure extends up to the first sub-area of the first conductive trace.

14. The chip according to claim 1, wherein the insulation layer is arranged continuously between the first conductive trace and the second conductive trace so that the first conductive trace is separated from the second conductive trace.

15. The chip according to claim 14, wherein the first conductive trace and the second conductive trace form the electrodes of a capacitor.

16. The chip according to claim 1, wherein the first active area and the second active area each comprise, on both sides of the first conductive trace, two contactings, which are formed either as contact structures or as dummy-contact structures.

17. The chip according to claim 1, wherein the first conductive trace and the second conductive trace each comprise two contactings, which are formed either as contact structures or as dummy-contact structures.