Electrostatic discharge protective device incorporating silicon controlled rectifier devices

• US 6,509,585 B2
• Filed: 03/20/2000
• Issued: 01/21/2003
• Est. Priority Date: 03/20/2000
• Status: Expired due to Fees

• Current Assignee: Winbond Electronics Corporation
• Original Assignee: Winbond Electronics Corporation
• Inventors: Huang, Chih-Yao
• Primary Examiner(s): Thomas, Tom
• Assistant Examiner(s): Nadav, Ori
• Application Number:
  US09/528,747
• Publication Number:
  US 20020134990A1
• Time in Patent Office: 1,037 Days
• Field of Search: 257/355-363, 257/173, 257/107, 361/56
• 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 29/0692 Surface layout
• CPC Class Codes: H01L 29/74 Thyristor-type devices, e.g. having four-zone regenerative action two-terminal thyristors H01L29/87

Abstract

An SCR cell structure provides a plurality of divided p+ and n+ blocks, and varies the spacing, sizes and locations of these divided p+ and n+ blocks to minimize latchup caused by non-ESD events. To further minimize latchup caused by non-ESD events, the SCR cell structure can also provide a plurality of divided blocks of Nwell and Psub pickup contacts, and varying the spacing, sizes, shapes and locations of these divided blocks of Nwell and Psub pickup contacts. In addition, the spacing of contact holes within the pickup contacts can also be varied to further minimize latchup caused by non-ESD events.

Claims

1. A silicon controlled rectifier (SCR) device used for electrostatic discharge protection, comprising:

an N-well region on which the SCR device is provided, the N-well region having a plurality of N+ blocks and P+ blocks that are connected to an anode;

a P substrate region on which the SCR device is provided, the P substrate region having a plurality of N+ blocks and P+ blocks that are connected to an cathode;

a first group of N+/P+ blocks where the P+ block of the first group is positioned in the N-well region and the N+ block of the first group is positioned in the P substrate region, and having a first spacing between the N+ block and the P+ block of the first group;

a second group of N+/P+ blocks where the P+ block of the second group is positioned in the N-well region and the N+ block of the second group is positioned in the P substrate region, and having a second spacing between the N+ block and the P+ block of the second group;

and wherein the first spacing is smaller than the second spacing.

2. The SCR of claim 1, further including a third group of N+/P+ blocks having an N+ block and a P+ block, and a third spacing between the N+ and P+ block of the group, and wherein the second spacing is smaller than the third spacing.

3. The SCR device of claim 2, wherein each P+ block and each N+ block has a corresponding pickup, and with each adjacent pickup separated by a distance, with the distance between the pickups for the first group and the pickups from the second group being smaller than the distance between the pickups for the second group and the pickups from the third group.

4. The SCR device of claim 1, wherein each N+ and P+ block of a group has a size, and wherein the size of the N+ and P+ blocks in the first group is larger than the size of the N+ and P+ blocks in the second group.

5. The SCR device of claim 1, wherein each P+ block and each N+ block has a corresponding pickup, with the pickups for the second group being larger than the pickups for the first group.

6. The SCR device of claim 1, wherein each P+ block and each N+ block has a corresponding pickup, with the pickups for the second group having a different shape than the pickups for the first group.

7. The SCR device of claim 1, wherein each P+ block and each N+ block has a corresponding pickup, with each pickup having contacts that are separated by a distance, and with the distance between the contacts of the pickups of the first group being greater than the distance between the contacts of the pickups of the second group.

8. The SCR of claim 1, wherein the first group is closer to a bonding pad than the second group.

9. A silicon controlled rectifier (SCR) device used for electrostatic discharge protection, comprising:

an N-well region on which the SCR device is provided, the N-well region having a plurality of N+ blocks and P+ blocks that are connected to an anode;

a P substrate region on which the SCR device is provided, the P substrate region having a plurality of N+ blocks and P+ blocks that are connected to an cathode;

a first group of N+/P+ blocks where the P+ block of the first group is positioned in the N-well region and the N+ block of the first group is positioned in the P substrate region, with each of the N+ blocks and the P+ blocks of the first group having a size;

a second group of N+/P+ blocks where the P+ block of the second group is positioned in the N-well region and the N+ block of the second group is positioned in the P substrate region, with each of the N+ blocks and the P+ blocks of the second group having a size;

and wherein the size of the N+ and P+ blocks in the first group is larger than the size of the N+ and P+ blocks in the second group.

10. The SCR of claim 9, further including a third group of N+/P+ blocks having an N+ block and a P+ block, and with each of the N+ and P+ blocks of the third group having a size, and wherein the size of the N+ and P+ blocks in the second group is larger than the size of the N+ and P+ blocks in the third group.

11. The SCR device of claim 10, wherein each P+ block and each N+ block has a corresponding pickup, and with each adjacent pickup separated by a distance, with the distance between the pickups for the first group and the pickups from the second group being smaller than the distance between the pickups for the second group and the pickups from the third group.

12. The SCR device of claim 9, wherein each P+ block and each N+ block has a corresponding pickup, with the pickups for the second group being larger than the pickups for the first group.

13. The SCR device of claim 9, wherein each P+ block and each N+ block has a corresponding pickup, with the pickups for the second group having a different shape than the pickups for the first group.

14. The SCR device of claim 9, wherein each P+ block and each N+ block has a corresponding pickup, with each pickup having contacts that are separated by a distance, and with the distance between the contacts of the pickups of the first group being greater than the distance between the contacts of the pickups of the second group.

15. The SCR of claim 9, wherein the first group is closer to a bonding pad than the second group.

16. The SCR of claim 9, wherein the second group is closer to unwanted trigger sources than the first group.

17. A silicon controlled rectifier (SCR) device used for electrostatic discharge protection, comprising:

an N-well region on which the SCR device is provided, the N-well region having a plurality of N+ blocks and P+ blocks that are connected to an anode;

a P substrate region on which the SCR device is provided, the P substrate region having a plurality of N+ blocks and P+ blocks that are connected to an cathode;

a first group of N+/P+ blocks, a second group of N+/P+ blocks, and a third group of N+/P+ blocks, with each group of N+/P+ blocks having;

an N+ block and a P+ block, with each of the N+ and P+ block of the group having a size, with a distance between the N+ block and P+ block of the group;

wherein the distance for the first group is smaller than the distance for the second group; and

wherein the size of the N+ and P+ blocks in the first group is larger than the size of the N+ and P+ blocks in the second group; and

wherein the N+ block of the groups of N+/P+ blocks is positioned in the P substrate region, and the P+ block of the groups of N+/P+ blocks is positioned in the N-well region.

18. The SCR device of claim 17, wherein each P+ block and each N+ block has a corresponding pickup, with the pickups for the second group being larger than the pickups for the first group.

19. The SCR device of claim 18, wherein each P+ block and each N+ block has a corresponding pickup, with the pickups for the second group having a different shape than the pickups for the first group.

20. The SCR device of claim 18, wherein each P+ block and each N+ block has a corresponding pickup, with each pickup having contacts that are separated by a distance, and with the distance between the contacts of the pickups of the first group being greater than the distance between the contacts of the pickups of the second group.