STRUCTURE OF SILICON CONTROLLED RECTIFIER

• US 20090278168A1
• Filed: 05/07/2008
• Published: 11/12/2009
• Est. Priority Date: 05/07/2008
• Status: Active Grant

• Current Assignee: United Microelectronics Corporation
• Original Assignee: United Microelectronics Corporation
• Inventors: Hwang, Hsin-Yen, Su, Shu-Hsuan, Tang, Tien-Hao
• Granted Patent: US 7,638,857 B2
• Time in Patent Office: Days
• US Class Current: 257/173
• CPC Class Codes: H01L 27/0262 including a PNP transistor and a NPN transistor, wherein each of said transistors has its base coupled to the collector of the other transistor, e.g. silicon controlled rectifier [SCR] devices
• CPC Class Codes: H01L 29/0626 with a localised breakdown region, e.g. built-in avalanching region in self-protected thyristors H01L29/7424
• CPC Class Codes: H01L 29/866 Zener diodes
• CPC Class Codes: H01L 29/87 Thyristor diodes, e.g. Shockley diodes, break-over diodes

Abstract

A silicon controlled rectifier structure is provided in a substrate having a first conductive type. A well region formed within the substrate has a second conductive type. A first dopant region formed within the substrate and the well region has the first conductive type. A second dopant region formed within the substrate and a portion of the well region has the second conductive type. A third dopant region formed under the second dopant region has the first conductive type, in which the second and the third regions form a vertical Zener diode. A fourth dopant region formed within the substrate and separated from the second dopant region by a separation structure has the second conductive type. A fifth dopant region is formed within the substrate in a manner that the fourth dopant region is between the isolation structure and the fifth dopant region, and has the first conductive type.

Claims

1. A structure of a silicon controlled rectifier, comprising:

a substrate, having a first conductive type;

a well region, formed within the substrate, having a second conductive type;

a first dopant region, formed within the substrate and the well region, and having the first conductive type;

a second dopant region, formed within the substrate and a portion of the well region, and having the second conductive type;

a third dopant region, formed under the second dopant region and having the first conductive type, wherein the second and the third regions forms a vertical Zener diode;

a fourth dopant region, formed within the substrate and separated from the second dopant region, having the second conductive type; and

a fifth dopant region, formed within the substrate in a manner that the fourth dopant region is between the second dopant region and the fifth dopant region, and having the first conductive type, wherein the second dopant region is between the first dopant region and the fourth dopant region.

2. The structure of claim 1, wherein a width of the third dopant region is equal or less than a width of the second dopant region.

3. The structure of claim 1, further comprising a sixth dopant region, formed within the substrate and the well regions, and having the second conductive type.

4. The structure of claim 1, further comprising a seventh dopant region, formed between the second dopant region and an isolation structure, having the first conductive type, wherein the third dopant region is located under the second and the seventh dopant regions.

5. The structure of claim 1, further comprising a plurality of isolation structures, arranged in a manner that the first, the second, the fourth and the fifth are respectively formed between two neighbor isolation structures.

6. The structure of claim 3, further comprising a plurality of isolation structures, arranged in a manner that the sixth, the first, the second, the fourth and the fifth are respectively formed between two neighbor isolation structures.

7. The structure of claim 1, further comprising:

a first contact for electrically connecting the fourth and the fifth dopant regions to serve as a cathode of the silicon controlled rectified; and

a second contact for electrically connecting the first dopant region to serve as an anode of the silicon controlled rectified.

8. The structure of claim 3, further comprising:

a first contact for electrically connecting the fourth and the fifth dopant regions to serve as a cathode of the silicon controlled rectified; and

a second contact for electrically connecting the first and the sixth dopant regions to serve as an anode of the silicon controlled rectified.

9. The structure of claim 4, wherein the isolation structure is a shallow trench isolation structure.

10. The structure of claim 1, wherein the first conductive type is P type, and the second conductive type is N type.

11. A structure of a silicon controlled rectifier, comprising:

a substrate, having a first conductive type;

a well region, formed within the substrate, having a second conductive type;

a first dopant region, formed within the substrate and the well region, and having the first conductive type;

a second dopant region, formed within the substrate and a portion of the well region, and having the first conductive type;

a third dopant region, formed under the second dopant region and having the second conductive type, wherein the second and the third regions forms a vertical Zener diode;

a fourth dopant region, formed within the substrate and separated from the second dopant region, having the second conductive type; and

a fifth dopant region, formed within the substrate in a manner that the fourth dopant region is between the second dopant region and the fifth dopant region, and having the first conductive type, wherein the second dopant region is between the first dopant region and the fourth dopant region.

12. The structure of claim 11, wherein a width of the third dopant region is equal or less than a width of the second dopant region.

13. The structure of claim 11, further comprising a sixth dopant region, formed within the substrate and the well regions, and having the second conductive type.

14. The structure of claim 11, further comprising a seventh dopant region, formed between the second dopant region and an isolation structure, having the second conductive type, wherein the third dopant region is located under the second and the seventh dopant regions.

15. The structure of claim 11, further comprising a plurality of isolation structures, arranged in a manner that the first, the second, the fourth and the fifth are respectively formed between two neighbor isolation structures.

16. The structure of claim 13, further comprising a plurality of isolation structures, arranged in a manner that the sixth, the first, the second, the fourth and the fifth are respectively formed between two neighbor isolation structures.

17. The structure of claim 11, further comprising:

a first contact for electrically connecting the fourth and the fifth dopant regions to serve as a cathode of the silicon controlled rectified; and

a second contact for electrically connecting the first dopant region to serve as an anode of the silicon controlled rectified.

18. The structure of claim 13, further comprising:

a first contact for electrically connecting the fourth and the fifth dopant regions to serve as a cathode of the silicon controlled rectified; and

a second contact for electrically connecting the first and the sixth dopant regions to serve as an anode of the silicon controlled rectified.

19. The structure of claim 14, wherein the isolation structure is a shallow trench isolation structure.

20. The structure of claim 11, wherein the first conductive type is P type, and the second conductive type is N type.