Silicon-controlled rectifiers having a cathode coupled by a contact with a diode trigger

Patent metadata

Field	Value
Publication number	US-10347622-B2
Application number	US-201715398946-A
Country	US
Kind code	B2
Filing date	Jan 5, 2017
Priority date	Jan 5, 2017
Publication date	Jul 9, 2019
Grant date	Jul 9, 2019

Abstract

Silicon-controlled rectifiers, electrostatic discharge circuits, and methods of fabricating a silicon-controlled rectifier for use in an electrostatic discharge circuit. A device structure for the silicon controlled rectifier includes a first well of a first conductivity type in a semiconductor layer, a second well of a second conductivity type in the semiconductor layer, a cathode coupled with the first well, and an anode coupled with the second well. First and second body contacts are coupled with the first well, and the first and second body contacts each have the first conductivity type. A triggering device may be coupled with the first body contact.

First claim

What is claimed is:

1. A device structure for a silicon controlled rectifier, the device structure comprising:
a first well of a first conductivity type in a semiconductor layer;
a second well of a second conductivity type in the semiconductor layer;
a cathode coupled with the first well;
an anode coupled with the second well;
a first body contact coupled with the first well, the first body contact having the first conductivity type; and
a second body contact coupled with the first well, the second body contact having the first conductivity type,
wherein the first well includes a first section that is arranged between the cathode and the first body contact, the first well includes a second section that is arranged between the first body contact and the second body contact, and the cathode is arranged between the first body contact and the anode.

2. The device structure of claim 1 wherein the first body contact comprises a first doped region of the first conductivity type in the first well, the second body contact comprises a second doped region of the first conductivity type in the first well, and the first doped region and the second doped region each have a dopant concentration that is greater than a dopant concentration of the first well.

3. The device structure of claim 2 wherein the cathode comprises a third doped region of the second conductivity type in the first well, and the anode comprises a doped region of the first conductivity type in the second well.

4. A device structure for a silicon controlled rectifier, the device structure comprising:
a first well of a first conductivity type in a semiconductor layer;
a second well of a second conductivity type in the semiconductor layer;
a cathode coupled with the first well;
an anode coupled with the second well;
a first semiconductor fin that projects upward from the first well;
a second semiconductor fin that projects upward from the first well;
an insulating layer arranged to surround respective lower portions of the first semiconductor fin and the second semiconductor fin;
a first body contact arranged in an upper portion of the first semiconductor fin above the insulating layer, the first body contact having the first conductivity type and a first dopant concentration that is greater than a dopant concentration of the first well; and
a second body contact arranged in an upper portion of the second semiconductor fin above the insulating layer, the second body contact having the first conductivity type and a second dopant concentration that is greater than a dopant concentration of the first well.

5. The device structure of claim 4 wherein the first semiconductor fin is separated from the second semiconductor fin by a section of the first well.

6. The device structure of claim 4 wherein the first semiconductor fin has a lengthwise parallel alignment with the first semiconductor fin.

7. The device structure of claim 4 wherein the cathode comprises a third semiconductor fin projecting from the first well, the anode comprises a fourth semiconductor fin projecting from the second well, the third semiconductor fin is comprised of semiconductor material having the second conductivity type, and the fourth semiconductor fin is comprised of semiconductor material having the first conductivity type.

8. The device structure of claim 4 wherein the first body contact is further arranged in a portion of a third semiconductor fin projecting from the first well, and the second body contact is further arranged in a portion of a fourth semiconductor fin projecting from the first well.

9. An electrostatic discharge protection circuit comprising:
a silicon controlled rectifier including a first well of a first conductivity type in a semiconductor layer, a second well of a second conductivity type in the semiconductor layer, a cathode coupled with the first well, an anode coupled with the second well, a first body contact coupled with the first well, and a second body contact coupled with the first well, the first body contact and the second body contact each having the first conductivity type; and
a triggering device coupled with the first body contact,
wherein the first well includes a first section that is arranged between the cathode and the first body contact, the first well includes a second section that is arranged between the first body contact and the second body contact, and the cathode is arranged between the first body contact and the anode.

10. An electrostatic discharge protection circuit comprising:
a silicon controlled rectifier including a first well of a first conductivity type in a semiconductor layer, a second well of a second conductivity type in the semiconductor layer, a cathode coupled with the first well, an anode coupled with the second well, a first body contact coupled with the first well, and a second body contact coupled with the first well, the first body contact and the second body contact each having the first conductivity type; and
a triggering device coupled with the first body contact,
wherein the first body contact comprises a first semiconductor fin projecting from the first well, the second body contact comprises a second semiconductor fin projecting from the first well, and the first semiconductor fin and the second semiconductor fin each contain a dopant concentration that is greater than a dopant concentration of the first well; and
wherein the triggering device is a diode that includes a third well of the first conductivity type in the semiconductor layer, a third semiconductor fin projecting from the third well, a fourth semiconductor fin projecting from the third well, the third semiconductor fin is comprised of semiconductor material having the first conductivity type, and the fourth semiconductor fin is comprised of semiconductor material having the second conductivity type.

11. The electrostatic discharge protection circuit of claim 10 wherein the first semiconductor fin is separated from the second semiconductor fin by a section of the first well.

12. The electrostatic discharge protection circuit of claim 11 wherein the cathode comprises a fifth semiconductor fin projecting from the first well, the anode comprises a sixth semiconductor fin projecting from the second well, the fifth semiconductor fin is comprised of semiconductor material having the second conductivity type, and the sixth semiconductor fin is comprised of semiconductor material having the first conductivity type.

13. The electrostatic discharge protection circuit of claim 11 wherein the first body contact comprises a fifth semiconductor fin projecting from the first well, the second body contact comprises a sixth semiconductor fin projecting from the first well, and the fifth semiconductor fin and the sixth semiconductor fin each have the dopant concentration that is greater than the dopant concentration of the first well.

14. The electrostatic discharge protection circuit of claim 9 wherein the first body contact comprises a first doped region of the first conductivity type in the first well, the second body contact comprises a second doped region of the first conductivity type in the first well, and the first doped region and the second doped region each have a dopant concentration that is greater than a dopant concentration of the first well.

15. The electrostatic discharge protection circuit of claim 14 wherein the cathode comprises a third doped region of the second conductivity type in the first well, and the anode comprises a doped region of the first conductivity type in the second well.

Assignees

• Globalfoundries Inc

Inventors

• Li You
• Prabu Manjunatha
• Muhammad Mujahid
• Campi Jr John B
• Gauthier Jr Robert J
• Mitra Souvick

Classifications

• H01L29/7436

  Electricity · mapped topic

• H01L29/0834

  Electricity · mapped topic

• H01L29/0653

  Electricity · mapped topic

• H01L27/0262 Primary

  Electricity · mapped topic

• H01L27/0641

  Electricity · mapped topic