Electrostatic discharge protection apparatus

Abstract

An electrostatic discharge protection device includes a substrate, a first well region, a second well region, a first doped region, a second doped region, a third doped region, a first terminal, and a second terminal. The first well region is disposed in the substrate and has a first conductivity type. The second well region is disposed in the first well region and has a second conductivity type, which is different from the first conductivity type. The first doped region is disposed in the first well region and has the first conductivity type. The second doped region is disposed in the first well region and has the second conductivity type. The third doped region is disposed in the second well region and has the first conductivity type. The second doped region is disposed between the first doped region and the third doped region. The first terminal is electrically connected to the first doped region and the third doped region. The second terminal is electrically connected to the second doped region.

Claims

1. An electrostatic discharge protection device, comprising: A substrate: A first well region is disposed in the substrate, the first well region having a first conductivity type; A second well region is disposed within the first well region, the second well region having a second conductivity type different from the first conductivity type; a first doped region is disposed within the first well region, the first doped region having the first conductivity type; a second doped region is disposed within the first well region, the second doped region having the second conductivity type; a third doped region is disposed within the second well region, the third doped region having the first conductivity type, wherein the second doped region is disposed between the first doped region and the third doped region; a first terminal electrically connected to the first doped region and the third doped region; and a second terminal electrically connected to the second doped region.

2. The electrostatic discharge protection device as described in claim 1, wherein the second well zone is a floating connection.

3. The electrostatic discharge protection device as claimed in claim 1, wherein the second doped region, at least a portion of the first well region, the second well region and the third doped region constitute a silicon controlled rectifier, and an electrostatic discharge current entering the third doped region flows to the second doped region through the silicon controlled rectifier.

4. The electrostatic discharge protection device as claimed in claim 1 further includes a third well region disposed in the substrate and having the second conductivity type, wherein the first well region includes an inner well region and an outer well region separated from each other, the second well region and the inner well region are disposed in the third well region, and the outer well region is adjacent to the second well region.

5. The electrostatic discharge protection device as described in claim 4, wherein the depth of the third well zone is greater than the depth of the second well zone.

6. The electrostatic discharge protection device as claimed in claim 1 further includes a fourth doped region, wherein the fourth doped region is disposed between the second doped region and the third doped region.

7. The electrostatic discharge protection device as claimed in claim 6, wherein the fourth doped region has the second conductivity type.

8. The electrostatic discharge protection device as claimed in claim 6, wherein the fourth doped region has the first conductivity type.

9. The electrostatic discharge protection device as claimed in claim 1, wherein the third doped region extends over the first well region and a portion of the second well region.

10. The electrostatic discharge protection device as claimed in claim 9 further includes a first gate structure disposed on the substrate and between the second doped region and the third doped region.

11. The electrostatic discharge protection device as claimed in claim 1 further includes a first isolation structure, a second isolation structure and a third isolation structure, wherein the second isolation structure is disposed between the first isolation structure and the third isolation structure, the first isolation structure is adjacent to the first doped region, and the third isolation structure is adjacent to the third doped region.

12. The electrostatic discharge protection device as claimed in claim 11 further includes a fourth isolation structure, wherein the fourth isolation structure is disposed between the second isolation structure and the third isolation structure, and between the second doped region and the third doped region.

13. The electrostatic discharge protection device as claimed in claim 12 further includes a fifth isolation structure and a fourth doped region, wherein the fourth doped region is disposed between the second doped region and the third doped region, and the fifth isolation structure is disposed between the fourth isolation structure and the second isolation structure, and between the second doped region and the fourth doped region.

14. The electrostatic discharge protection device as claimed in claim 6 further includes a first gate structure and a second gate structure disposed on the substrate, wherein the first gate structure is disposed between the second doped region and the fourth doped region, and the second gate structure is disposed between the third doped region and the fourth doped region.

15. The electrostatic discharge protection device as claimed in claim 14, wherein the second gate structure is electrically connected to the first end.

16. The electrostatic discharge protection device as claimed in claim 14, wherein the fourth doped region is electrically connected to the first terminal.

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