Dummy fill scheme for use with passive devices

Patent metadata

Field	Value
Publication number	US-10867912-B2
Application number	US-201916248317-A
Country	US
Kind code	B2
Filing date	Jan 15, 2019
Priority date	Jan 15, 2019
Publication date	Dec 15, 2020
Grant date	Dec 15, 2020

Abstract

Structures that include a passive device, such as a metal-based resistor, and methods of forming a structure that includes a passive device. The structure includes a semiconductor substrate, an interconnect structure including a passive device, and a dummy fill region arranged between the passive device and the semiconductor substrate. The dummy fill region includes a plurality of shallow trench isolation regions in the semiconductor substrate, a plurality of semiconductor fins, a plurality of source/drain regions in the plurality of semiconductor fins, and a plurality of contacts arranged over the plurality of shallow trench isolation regions.

First claim

What is claimed is:

1. A structure comprising:
a semiconductor substrate;
an interconnect structure including a passive device; and
a dummy fill region arranged between the passive device and the semiconductor substrate, the dummy fill region including a plurality of shallow trench isolation regions in the semiconductor substrate, a plurality of semiconductor fins, a plurality of gate structures, a plurality of source/drain regions in the plurality of semiconductor fins, a plurality of contacts arranged over the plurality of shallow trench isolation regions, and each contact including a metal silicide layer in direct physical contact with one of the plurality of shallow trench isolation regions; and
a moat region in the semiconductor substrate beneath the dummy fill region,
wherein the moat region contains a dopant concentration that is less than or equal to 5×10 15 cm −3 .

2. The structure of claim 1 wherein the semiconductor substrate has a top surface, the plurality of shallow trench isolation regions extend from the top surface of the semiconductor substrate to a first depth, and the moat region extends from the top surface of the semiconductor substrate to a second depth that is greater than the first depth of the plurality of shallow trench isolation regions.

3. The structure of claim 1 wherein the plurality of shallow trench isolation regions surround a plurality of sections of the moat region that are respectively arranged beneath the plurality of semiconductor fins.

4. The structure of claim 1 further comprising:
an interlayer dielectric layer including a plurality of sections arranged directly over the plurality of source/drain regions.

5. The structure of claim 4 wherein the plurality of source/drain regions are not contacted by the plurality of contacts, and the plurality of contacts are only arranged over the plurality of shallow trench isolation regions.

6. The structure of claim 4 wherein the plurality of gate structures are arranged to overlap with the plurality of semiconductor fins, the plurality of source/drain regions are arranged in the plurality of semiconductor fins between the plurality of gate structures, and the plurality of sections of the interlayer dielectric layer are arranged over the plurality of source/drain regions respectively between the plurality of gate structures.

7. The structure of claim 1 wherein the passive device is displaced in a vertical direction from the dummy fill region, the dummy fill region includes a first plurality of edges, and the passive device includes a second plurality of edges that are substantially aligned with the first plurality of edges of the dummy fill region.

8. The structure of claim 7 wherein the first plurality of edges of the dummy fill region are substantially aligned in two orthogonal directions with the second plurality of edges of the passive device.

9. The structure of claim 1 wherein the passive device is a thin film resistor.

10. The structure of claim 1 wherein the plurality of gate structures are arranged to overlap with the plurality of semiconductor fins and the plurality of shallow trench isolation regions, and the plurality of contacts are arranged over the plurality of shallow trench isolation regions respectively between the plurality of gate structures.

11. A structure comprising:
a semiconductor substrate;
an interconnect structure including a passive device;
a dummy fill region arranged between the passive device and the semiconductor substrate, the dummy fill region including a plurality of shallow trench isolation regions in the semiconductor substrate, a plurality of semiconductor fins, a plurality of gate structures, a plurality of source/drain regions in the plurality of semiconductor fins, and a plurality of contacts arranged over the plurality of shallow trench isolation regions; and
a moat region in the semiconductor substrate beneath the dummy fill region,
wherein the plurality of contacts have a directly contacting relationship with the plurality of shallow trench isolation regions, the plurality of gate structures are arranged to overlap with the plurality of semiconductor fins and the plurality of shallow trench isolation regions, the plurality of contacts are arranged over the plurality of shallow trench isolation regions respectively between the plurality of gate structures, and the moat region contains a dopant concentration that is less than or equal to 5×10 15 cm −3 .

12. A method comprising:
forming a plurality of semiconductor fins projecting from a semiconductor substrate;
forming a plurality of shallow trench isolation regions in the semiconductor substrate that surround the plurality of semiconductor fins;
forming a plurality of source/drain regions in the plurality of semiconductor fins;
forming a plurality of contacts arranged over the plurality of shallow trench isolation regions;
forming a moat region in the semiconductor substrate beneath a dummy fill region provided by the plurality of semiconductor fins, the plurality of contacts, and the plurality of shallow trench isolation regions; and
forming an interconnect structure including a passive device arranged over the dummy fill region,
wherein each contact includes a metal silicide layer in direct physical contact with one of the shallow trench isolation regions, and the moat region contains a dopant concentration that is less than or equal to 5×10 15 cm −3 .

13. The method of claim 12 further comprising:
forming sections of an interlayer dielectric layer including a plurality of sections arranged directly over the plurality of source/drain regions; and
forming a plurality of gate structures arranged to overlap with the plurality of semiconductor fins,
wherein the plurality of source/drain regions are arranged in the plurality of semiconductor fins between the plurality of gate structures, and the plurality of sections of the interlayer dielectric layer are arranged over the plurality of source/drain regions between the plurality of gate structures.

14. The method of claim 12 wherein the passive device is displaced in a vertical direction from the dummy fill region, the dummy fill region includes a first plurality of edges, and the passive device includes a second plurality of edges that are substantially aligned in two orthogonal directions with the first plurality of edges of the dummy fill region.

15. The method of claim 12 wherein the passive device is a thin film resistor.

16. The method of claim 12 further comprising:
forming a plurality of gate structures arranged to overlap with the plurality of semiconductor fins and the plurality of shallow trench isolation regions,
wherein the plurality of contacts are arranged over the plurality of shallow trench isolation regions between the plurality of gate structures.

Assignees

• Globalfoundries Inc

Inventors

• Mehta Jaladhi
• Greene Brian
• Dechene Daniel J
• Hassan Ahmed

Classifications

• H10W20/496

  Capacitor integral with wiring layers · CPC title

• H10W10/01

  Manufacture or treatment · CPC title

• H10W10/00

  Isolation regions in semiconductor bodies between components of integrated devices · CPC title

• H10W10/17

  formed using trench refilling with dielectric materials, e.g. shallow trench isolations · CPC title

• H10W10/014

  using trench refilling with dielectric materials, e.g. shallow trench isolations · CPC title