Reprogrammable metal-to-metal antifuse employing carbon-containing antifuse material

• US 7,459,763 B1
• Filed: 02/20/2004
• Issued: 12/02/2008
• Est. Priority Date: 10/02/2001
• Status: Expired due to Term

• Current Assignee: Microsemi SoC Corp. (Microchip Technology Incorporated)
• Original Assignee: Actel Corporation (Microchip Technology Incorporated)
• Inventors: Issaq, A. Farid, McCollum, John, Hawley, Frank
• Primary Examiner(s): Nadav, Ori
• Application Number:
  US10/784,903
• Time in Patent Office: 1,747 Days
• Field of Search: 257 76- 77, 257529-530, 257/751, 257/774
• US Class Current: 257/530
• CPC Class Codes: G11C 17/16 using electrically-fusible links
• CPC Class Codes: H01L 23/5252 comprising anti-fuses, i.e. connections having their state changed from non-conductive to 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
• CPC Class Codes: H01L 2924/3011 Impedance

Abstract

A reprogrammable metal-to-metal antifuse is disposed between two metal interconnect layers in an integrated circuit. A lower barrier layer is formed from Ti. A lower adhesion-promoting layer is disposed over the lower Ti barrier layer. An antifuse material layer selected from a group comprising at least one of amorphous carbon and amorphous carbon doped with at least one of hydrogen and fluorine is disposed over the lower adhesion-promoting layer. An upper adhesion-promoting layer is disposed over the antifuse material layer. An upper Ti barrier layer is disposed over the upper adhesion-promoting layer.

Claims

1. A reprogrammable metal-to-metal antifuse comprising:

an inter-metal dielectric layer having a via formed therethrough and filled with a metal plug;

a lower Ti barrier layer disposed over said metal plug;

a lower adhesion-promoting layer disposed over said lower Ti barrier layer;

an antifuse material layer disposed above an upper surface of said lower adhesion-promoting layer, said antifuse material layer selected from a group comprising at least one of amorphous carbon and amorphous carbon doped with at least one of hydrogen and fluorine disposed over said lower adhesion-promoting layer;

an upper adhesion-promoting layer disposed over said antifuse material layer; and

an upper Ti barrier layer disposed over said upper adhesion-promoting layer,

wherein;

said lower adhesion-promoting layer and said upper adhesion-promoting layer each have a thickness of between about 2 angstroms and about 20 angstroms;

the reprogrammable metal-to-metal antifuse is programmed in response to a programming potential applied across the antifuse; and

the reprogrammable metal-to-metal antifuse is erased in response to an erasing potential, lower in magnitude than the programming potential, across the antifuse.

2. The reprogrammable metal-to-metal antifuse of claim 1, wherein said lower adhesion-promoting layer and said upper adhesion-promoting layer are comprised of a material selected from the group comprising Si_xC_y and Si_xN_y.

3. The reprogrammable metal-to-metal antifuse of claim 2, wherein said lower adhesion-promoting layer and said upper adhesion-promoting layer comprise Si_xC_y.

4. The reprogrammable metal-to-metal antifuse of claim 3, wherein a ratio of x to y in said Si_xC_y is in a range of about 1+/−

0.4.

5. The reprogrammable metal-to-metal antifuse of claim 2, wherein said lower adhesion-promoting layer and said upper adhesion-promoting layer comprise Si_xN_y.

6. The reprogrammable metal-to-metal antifuse of claim 5, wherein a ratio of x to y in said Si_xN_y is in a range of about 0.75+/−

0.225.

7. The reprogrammable metal-to-metal antifuse of claim 1, wherein said lower adhesion-promoting layer and said upper adhesion-promoting layer are from a material selected from the group comprising Si_xC_y and Si_xN_y.

8. The reprogrammable metal-to-metal antifuse of claim 7, wherein said lower adhesion-promoting layer and said upper adhesion-promoting layer comprise Si_xC_y.

9. The reprogrammable metal-to-metal antifuse of claim 8, wherein a ratio of x to y in said Si_xC_y is in a range of about 1+/−

0.4.

10. The reprogrammable metal-to-metal antifuse of claim 7, wherein said lower adhesion-promoting layer and said upper adhesion-promoting layer comprise Si_xN_y.

11. The reprogrammable metal-to-metal antifuse of claim 7, wherein a ratio of x to y in said Si_xN_y is in a range of about 0.75+/−

0.225.

12. The reprogrammable metal-to-metal antifuse of claim 1, wherein said antifuse material layer is formed from amorphous carbon having a thickness of between about 50 angstroms and about 500 angstroms.

13. The reprogrammable metal-to-metal antifuse of claim 1, wherein said antifuse material layer comprises amorphous carbon doped with hydrogen in a concentration range of about 1 atomic percent to about 40 atomic percent.

14. The reprogrammable metal-to-metal antifuse of claim 13, wherein said antifuse material layer has a thickness of between about 50 angstroms and about 500 angstroms.

15. The reprogrammable metal-to-metal antifuse of claim 1, wherein said antifuse material layer is about 50 angstroms to 500 angstroms in thickness, and said lower adhesion-promoting layer and said upper adhesion-promoting layer each have a thickness of between about 2 angstroms and about 20 angstroms.

16. The reprogrammable metal-to-metal antifuse in claim 15, wherein said lower adhesion-promoting layer and said upper adhesion-promoting layer are from a material selected from the group comprising Si_xC_y and Si_xN_y.

17. The reprogrammable metal-to-metal antifuse of claim 16, wherein said lower adhesion-promoting layer and said upper adhesion-promoting layer comprise Si_xC_y.

18. The reprogrammable metal-to-metal antifuse of claim 17, wherein a ratio of x to y in said Si_xC_y is in a range of about 1+/−

0.4.

19. The reprogrammable metal-to-metal antifuse of claim 16, wherein said lower adhesion-promoting layer and said upper adhesion-promoting layer comprise Si_xN_y.

20. The reprogrammable metal-to-metal antifuse of claim 19, wherein a ratio of x to y in said Si_xN_y is in a range of about 0.75+/−

0.225.

21. The reprogrammable metal-to-metal antifuse of claim 16, wherein said amorphous carbon antifuse material layer is doped with hydrogen from about 1 atomic percent to about 40 atomic percent.

22. A reprogrammable metal-to-metal antifuse comprising:

a lower metal interconnect layer;

an inter-metal dielectric layer disposed over said lower metal interconnect layer, said inter-metal dielectric layer having a via formed therethrough and filled with a metal plug;

a lower Ti barrier layer disposed over said metal plug;

a lower adhesion-promoting layer disposed over said lower Ti barrier layer;

an antifuse material layer formed from amorphous carbon and disposed over said lower adhesion-promoting layer;

an upper adhesion-promoting layer disposed over said antifuse material layer;

an upper Ti barrier layer disposed over said upper adhesion-promoting layer; and

an upper metal interconnect layer disposed over said upper Ti barrier layer,

wherein said lower adhesion-promoting layer and said upper adhesion-promoting layer each have a thickness of between about 2 angstroms and about 20 angstroms;

the reprogrammable metal-to-metal antifuse is programmed in response to a programming potential applied across the antifuse; and

the reprogrammable metal-to-metal antifuse is erased in response to an erasing potential, lower in magnitude than the programming potential, across the antifuse.

23. The reprogrammable metal-to-metal antifuse of claim 22, wherein said lower adhesion-promoting layer and said upper adhesion-promoting layer are comprised of a material selected from the group comprising Si_xC_y and Si_xN_y.

24. The reprogrammable metal-to-metal antifuse of claim 23, wherein said lower adhesion-promoting layer and said upper adhesion-promoting layer comprise Si_xC_y.

25. The reprogrammable metal-to-metal antifuse of claim 24, wherein a ratio of x to y in said Si_xC_y is in a range of about 1+/−

0.4.

26. The reprogrammable metal-to-metal antifuse of claim 23, wherein said lower adhesion-promoting layer and said upper adhesion-promoting layer comprise Si_xN_y.

27. The reprogrammable metal-to-metal antifuse of claim 26, wherein a ratio of x to y in said Si_xN_y is in a range of about 0.75+/−

0.225.

28. The reprogrammable metal-to-metal antifuse of claim 22, wherein said antifuse material layer has a thickness of between about 50 angstroms and about 500 angstroms.

29. The reprogrammable metal-to-metal antifuse of claim 22, wherein said amorphous carbon antifuse material layer is doped with hydrogen in a concentration range of about 1 atomic percent to about 40 atomic percent.

30. The reprogrammable metal-to-metal antifuse of claim 29, wherein said amorphous carbon antifuse material layer has a thickness of between about 50 angstroms and about 500 angstroms.

31. The reprogrammable metal-to-metal antifuse of claim 22, wherein said lower adhesion-promoting layer and said upper adhesion-promoting layer are comprised of a material selected from the group comprising Si_xC_y, Si_xN_y, Si_xC_yN_z, Si_xO_yC_z, and Si_xO_yN_z.

32. A reprogrammable metal-to-metal antifuse comprising:

an inter-metal dielectric layer having a via formed therethrough and filled with a metal plug;

a lower Ti barrier layer disposed over said metal plug;

a lower Si_xC_y layer disposed over said lower Ti barrier layer;

an antifuse material layer comprised of amorphous carbon and disposed over said lower Si_xC_y layer;

an upper Si_xC_y layer disposed over said antifuse material layer; and

an upper Ti barrier layer,

wherein said lower Si_xC_y layer and said upper Si_xC_y layer each have a thickness of between about 2 angstroms and about 20 angstroms;

the reprogrammable metal-to-metal antifuse is programmed in response to a programming potential applied across the antifuse; and

the reprogrammable metal-to-metal antifuse is erased in response to an erasing potential, lower in magnitude than the programming potential, across the antifuse.

33. A reprogrammable metal-to-metal antifuse comprising:

an inter-metal dielectric layer having a via formed therethrough and filled with a metal plug;

a lower Ti barrier layer disposed over said metal plug;

a lower Si_xN_y layer disposed over said lower Ti barrier layer;

an antifuse material layer comprised of amorphous carbon and disposed over said lower Si_xN_y layer;

an upper Si_xN_y layer disposed over said antifuse material layer; and

an upper Ti barrier layer,

wherein said lower Si_xN_y layer and said upper Si_xN_y layer each have a thickness of between about 2 angstroms and about 20 angstroms;

the reprogrammable metal-to-metal antifuse is programmed in response to a programming potential applied across the antifuse; and

the reprogrammable metal-to-metal antifuse is erased in response to an erasing potential, lower in magnitude than the programming potential, across the antifuse.