Electrostatic discharge (ESD) clamp

• US 9,716,016 B2
• Filed: 12/20/2012
• Issued: 07/25/2017
• Est. Priority Date: 12/20/2012
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Hsu, Chia-Wei
• Primary Examiner(s): Smith, Bradley K
• Assistant Examiner(s): GOODWIN, DAVID J
• Application Number:
  US13/721,431
• Publication Number:
  US 20140175611A1
• Time in Patent Office: 1,678 Days
• Field of Search: 257124, 257173, 257121, 257355, 257360, 257199, 257362
• CPC Class Codes: H01L 21/4846 Leads on or in insulating or insulated substrates, e.g. metallisation H01L21/4821 takes precedence; metallisation of ceramics in general C04B41/51; printed circuits H05K3/00
• CPC Class Codes: H01L 27/0248 for electrical or thermal protection, e.g. electrostatic discharge [ESD] protection

Abstract

One or more techniques or systems for forming an electrostatic discharge (ESD) clamp are provided herein. In some embodiments, the ESD clamp includes a first pad and a second pad. For example, the first pad is a positive supply voltage (Vdd) pad and the second pad is a negative supply voltage (Vss) pad. In some embodiments, active regions and oxide regions are associated with substantially rounded shapes or obtuse angles. Additionally, metal regions are configured to be in contact with at least some of at least one of the active regions or the oxide regions and the first pad. In some embodiments, the metal regions are substantially wedge shaped. In this manner, an ESD clamp with enhanced performance is provided, at least because the respective active regions are substantially rounded or associated with obtuse angles, for example.

Claims

1. An electrostatic discharge (ESD) clamp, comprising:

a first pad;

a first active region electrically coupled to the first pad and associated with a first active substantially rounded shape;

a first oxide region associated with a first oxide substantially rounded shape, the first oxide region encompassing at least some of the first active region;

a second active region associated with a second active substantially rounded shape, the second active region encompassing at least some of the first oxide region;

a second oxide region associated with a second oxide substantially rounded shape, the second oxide region encompassing at least some of the second active region;

a third active region associated with a third active substantially rounded shape, the third active region encompassing at least some of the second oxide region, wherein the second active region is between the first active region and the third active region;

a second pad electrically coupled to a first portion of the third active region;

a third pad electrically coupled to a second portion of the third active region; and

a metal layer divided into a plurality of wedges, the second pad electrically coupled to a first wedge of the plurality of wedges and the third pad electrically coupled to a second wedge of the plurality of wedges, wherein the first wedge is adjacent the second wedge and not in contact with the second wedge.

2. The ESD clamp of claim 1, wherein the first wedge provides a first current discharge path and the second wedge provides a second current discharge path different than the first current discharge path.

3. The ESD clamp of claim 1, the first active region associated with a first active thickness.

4. The ESD clamp of claim 1, the first oxide region associated with a first oxide thickness.

5. The ESD clamp of claim 1, the second active region associated with a second active thickness.

6. The ESD clamp of claim 1, the second active region in contact with the first oxide region and the second oxide region.

7. The ESD clamp of claim 1, comprising one or more additional oxide regions associated with a substantially rounded shape.

8. The ESD clamp of claim 1, comprising a number of active regions based on a design parameter.

9. The ESD clamp of claim 1, comprising a number of oxide regions based on a design parameter.

10. The ESD clamp of claim 1, the second pad and the third pad associated with a negative supply voltage (Vss).

11. The ESD clamp of claim 1, comprising:

a first substantially wedged shape metal region electrically coupled to the second pad; and

a second substantially wedged shaped metal region electrically coupled to the third pad.

12. The ESD clamp of claim 1, the first active region comprising silicon.

13. The ESD clamp of claim 1, the second active region comprising silicon.

14. The ESD clamp of claim 1, the first active region forming a first closed loop, the second active region forming a second closed loop, and the third active region forming a third closed loop.

15. An electrostatic discharge (ESD) clamp, comprising:

a first pad;

a first active region electrically coupled to the first pad;

a first oxide region encompassing the first active region;

a second active region encompassing the first oxide region;

a second pad electrically coupled to a first portion of the second active region;

a third pad electrically coupled to a second portion of the second active region, the second pad different than the third pad; and

a metal layer over the second active region and divided into a plurality of wedges, a first wedge of the plurality of wedges electrically coupled to the second pad and the first portion of the second active region and a second wedge of the plurality of wedges electrically coupled to the third pad and the second portion of the second active region, wherein the first wedge is adjacent the second wedge and not in contact with the second wedge to provide distinct current discharge paths.

16. The ESD clamp of claim 15, comprising a third active region encompassing the second active region, the first wedge electrically coupled to a first portion of the third active region.

17. The ESD clamp of claim 15, the first pad associated with a positive supply voltage (Vdd).

18. The ESD clamp of claim 15, the second pad and the third pad associated with a negative supply voltage (Vss).

19. The ESD clamp of claim 15, at least some of at least one of the first active region, the first oxide region, or the second active region arranged in concentric formation.

20. A method for forming an electrostatic discharge (ESD) clamp, comprising:

forming a first pad;

forming a first active region associated with a first active substantially rounded shape;

forming a first oxide region associated with a first oxide substantially rounded shape, the first oxide region encompassing at least some of the first active region;

forming a second active region associated with a second active substantially rounded shape, the second active region encompassing at least some of the first oxide region;

forming a first wedge-shaped metal region, the first wedge-shaped metal region electrically coupled to a first portion of the second active region;

forming a second wedge-shaped metal region adjacent the first wedge-shaped metal region, the second wedge-shaped metal region electrically coupled to a second portion of the second active region and not in contact with the first wedge-shaped metal region;

electrically coupling a second pad to the first wedge-shaped metal region; and

electrically coupling a third pad to the second wedge-shaped metal region, the first wedge-shaped metal region providing a first current path and the second wedge-shaped metal region providing a second current path different than the first current path.