FinFET varactor quality factor improvement

Patent metadata

Field	Value
Publication number	US-11961836-B2
Application number	US-201816147205-A
Country	US
Kind code	B2
Filing date	Sep 28, 2018
Priority date	Sep 28, 2018
Publication date	Apr 16, 2024
Grant date	Apr 16, 2024

Abstract

An integrated circuit structure comprises one or more fins extending above a surface of a substrate over an N-type well. A gate is over and in contact with the one or more fins. A second shallow N-type doping is below the gate and above the N-type well.

First claim

What is claimed is:

1. An integrated circuit structure, comprising:
a plurality of fins extending above a surface of a substrate along a first direction, the plurality of fins spaced apart from one another;
a gate over the plurality of fins, the gate along a second direction substantially orthogonal with the first direction;
an insulating layer that surrounds and is in contact with respective ones of the plurality of fins in-between the substrate and the gate;
an N-type well located in the substrate below the plurality of fins; and
an N-type doping in the substrate between the plurality of fins and the N-type well, the N-type doping extending vertically from the substrate to only a portion a height of the respective ones of the plurality of fins that extend above the surface of the substrate and below the gate, wherein the N-type doping has a doping concentration of 2e18-7e18.

2. The integrated circuit structure of claim 1 , wherein the second N type doping has a doping depth of 70-120 nm.

3. The integrated circuit structure of claim 1 , wherein the plurality of fins comprise a first set of fins having a first fin height and a second set of fins having a second fin height, where the second fin height is less than the first fin height.

4. The integrated circuit structure of claim 3 , wherein the first fin height and the second fin height are measured between the substrate and respective gates.

5. The integrated circuit structure of claim 4 , wherein the first fin height is 120-140 nm and the second fin height is 45-50 nm.

6. A FinFET varactor, comprising:
an N-type well within a substrate;
a plurality of fins along a first direction extending above a surface of the substrate over the N-type well, the plurality of fins spaced apart from one another;
a plurality of gates over the plurality of fins that extend above the surface of a substrate, the plurality of gates along a second direction substantially orthogonal with the first direction;
an insulating layer that surrounds and is in contact with respective ones of the plurality of fins in-between the substrate and the plurality of gates; and
an N-type doping in the substrate between the plurality of fins and the N-type well, the N-type doping extending vertically from the substrate to only a portion a height of the respective ones of the plurality of fins that extend above the surface of the substrate and below the plurality of gates, wherein the N-type doping has a doping concentration of 2e18-7e18.

7. The FinFET varactor of claim 6 , wherein the N-type doping has a doping depth of 70-120 nm.

8. The FinFET varactor of claim 6 , wherein the plurality of fins comprise a first set of fins having a first fin height and a second set of fins having a second fin height, where the second fin height is less than the first fin height.

9. The FinFET varactor of claim 8 , wherein the first fin height and the second fin height are measured between the substrate and respective gates.

10. The FinFET varactor of claim 9 , wherein the first fin height is 120-140 nm and the second fin height is 45-50 nm.

Assignees

• Intel Corp

Inventors

• Lee Hyung-Jin
• Armstrong Mark
• Morarka Saurabh
• Nieva-Lozano Carlos
• Kar Ayan

Classifications

• H10D1/64

  Variable-capacitance diodes, e.g. varactors · CPC title

• H10D1/045

  of capacitors having potential barriers, e.g. varactors · CPC title

• H10D1/66

  Conductor-insulator-semiconductor capacitors, e.g. MOS capacitors · CPC title

• H10D84/834

  comprising FinFETs · CPC title

• H10D84/215 Primary

  of only varactors · CPC title