ELECTRICAL FUSES WITH REDUNDANCY

• US 20080252361A1
• Filed: 06/25/2008
• Published: 10/16/2008
• Est. Priority Date: 03/07/2005
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Chung, Shine Chien
• Granted Patent: US 7,724,601 B2
• Time in Patent Office: Days
• US Class Current: 327/525
• CPC Class Codes: G11C 17/14 in which contents are determined by selectively establishing, breaking or modifying connecting links by permanently altering the state of coupling elements, e.g. PROM
• CPC Class Codes: G11C 17/16 using electrically-fusible links
• CPC Class Codes: G11C 29/816 for an application-specific layout
• CPC Class Codes: G11C 29/846 by choosing redundant lines at an output stage
• CPC Class Codes: H01L 23/5256 comprising fuses, i.e. connections having their state changed from conductive to non-conductive
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

The present disclosure provides an electrical fuse cell with redundancy features and the method for operating the same. The fuse cell includes a first set of electrical fuses having at least one electrical fuse contained therein, and a second set of electrical fuses having at least one electrical fuse for providing redundancy to at least one fuse of the first set, wherein if one of the first set of electrical fuses is defective, at least one of the second set of the electrical fuses can be programmed to provide a redundancy function of the defective fuse.

Claims

1. An electrical fuse cell with redundancy features comprising:

a first set of electrical fuses having at least one electrical fuse contained therein; and

a second set of electrical fuses having at least one electrical fuse for providing redundancy to at least one fuse of the first set,

wherein if one of the first set of electrical fuses is defective, at least one of the second set of the electrical fuses can be programmed to provide a redundancy function of the defective fuse.

2. The cell of claim 1 wherein each electrical fuse is coupled with a programming device.

3. The cell of claim 2 wherein each electrical fuse is coupled with an output select device.

4. The cell of claim 1 further comprising at least one tag bit associated with the first set to indicate whether it is defective.

6. The cell of claim 1 wherein each fuse in the first set is correlated with one in the second set for providing programmed data based on a combination of their individually programmed data.

5. The cell of claim 5 wherein the tag bit is a pre-programmed fuse to determine a selection of the first set or the second set for use.

7. The cell of claim 5 wherein the first set is selected if the tag bit has not been programmed.

8. The cell of claim 5 wherein the second set is selected if the tag bit has been programmed.

9. The cell of claim 5 further comprising a first decoder for locating the fuse of the first set to be accessed based on an address provided by an address buffer and a second decoder for locating a redundant fuse from the second set for the fuse to be accessed in the first set.

10. An electrical fuse cell with redundancy features comprising:

a first set of electrical fuses having at least one electrical fuse contained therein, each fuse in the first set being coupled to an output select device and a programming device;

a second set of electrical fuses having at least one electrical fuse for providing redundancy to at least one fuse of the first set, each fuse in the second set being coupled to an output select device and a programming device, wherein if one of the first set of electrical fuses is defective, at least one of the second set of the electrical fuses can be programmed to provide a redundancy function of the defective fuse; and

at least one programmable tag bit associated with the first set to indicate whether the at least one fuse of first set is defective.

11. The cell of claim 10 wherein the tag bit is part of the fuse array.

12. The cell of claim 10 wherein the tag bit is readable via a read bit line to determine if the tag bit is programmed or not.

13. The cell of claim 10 wherein each fuse in the first set is correlated with one in the second set for providing programmed data based on a combination of their individually programmed data.

14. The cell of claim 10 further comprising a first decoder for locating the fuse of the first set to be accessed based on an address provided by an address buffer and a second decoder for locating a redundant fuse from the second set for the fuse to be accessed in the first set.

15. An electrical fuse cell with redundancy features comprising:

a first set of electrical fuses having at least one electrical fuse contained therein, each fuse in the first set being coupled to an output select device and a programming device;

a second set of electrical fuses having at least one electrical fuse for providing redundancy to at least one fuse of the first set, each fuse in the second set being coupled to an output select device and a programming device, wherein if one of the first set of electrical fuses is defective, at least one of the second set of the electrical fuses can be programmed to provide a redundancy function of the defective fuse;

a first decoder for locating the fuse of the first set to be accessed based on an address provided by an address buffer;

a second decoder for locating a redundant fuse from the second set for the fuse to be accessed in the first set; and

at least one programmable tag bit associated with the first set to indicate whether the at least one fuse of first set is defective.

16. The cell of claim 15 further comprising a redundant match address module being pre-programmed to contain the addresses of faulty bits in the first set.

17. The cell of claim 16 wherein the redundant match address module receives a signal from the address buffer to determine if the at least one fuse from the first set is defective.

18. The cell of claim 15 wherein the second decoder generates a signal to disable the first decoder if the at least one fuse of the first set is defective.

19. The cell of claim 15 wherein each fuse in the first set is correlated with one in the second set for providing programmed data based on a combination of their individually programmed data.

20. The cell of claim 15 further comprising an output selection module operable to select fuse data from the second set instead of from the first set to generate a final output signal from the fuse cell.