Low current redundancy anti-fuse method and apparatus

• US 6,351,140 B2
• Filed: 02/27/2001
• Issued: 02/26/2002
• Est. Priority Date: 10/03/1996
• Status: Expired due to Fees

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Ho, Fan, Beigel, Kurt D., Cutter, Douglas J.
• Primary Examiner(s): Tokar, Michael
• Assistant Examiner(s): Le, Don Phu
• Application Number:
  US09/794,683
• Publication Number:
  US 20010008382A1
• Time in Patent Office: 364 Days
• Field of Search: 326/37-41, 326/83, 326/82, 326/86, 326/10, 327/525
• US Class Current: 326/38
• CPC Class Codes: G11C 17/18 Auxiliary circuits, e.g. for writing into memory
• CPC Class Codes: G11C 29/785 with redundancy programming schemes
• CPC Class Codes: G11C 29/83 with reduced power consumption

Abstract

A programmable circuit includes a first node and provides a programmed signal based on the state of the first node. A first anti-fuse has a programmed state and an unprogrammed state and couples the first node to a first power supply when in the programmed state and decouples the first node from the first power supply when in the unprogrammed state. A second anti-fuse has a programmed state and an unprogrammed state and couples the first node to a second power supply when in the programmed state and decouples the first node from the second power supply when in the unprogrammed state. The state of the programmed signal can be used to replace a primary circuit element of an integrated circuit with a redundant circuit element.

Claims

1. A programmable circuit for providing a programmed signal in an integrated circuit, comprising:

a first node, wherein the state of the programmed signal is based on the state of the first node;

a first anti-fuse for selectively coupling the first node to a first power supply when in a programmed state and decoupling the first node from the first power supply when in an unprogrammed state;

a second anti-fuse for selectively coupling the first node to a second power supply when in a programmed state and decoupling the first node from the second power supply when in an unprogrammed state; and

a switch for selectively coupling the first node to the second power supply regardless of the state of the second anti-fuse.

2. The programmable circuit of claim 1, wherein the second power supply is a ground potential.

3. The programmable circuit of claim 1, wherein no long-L p-channel pull-up transistor is interposed between the first node and the first power supply.

4. The programmable circuit of claim 1, wherein no long-L p-channel pull-up transistor is interposed between the first node and the second power supply.

5. The programmable circuit of claim 1, wherein no long-L p-channel pull-up transistor is interposed between the first node and both of the first power supply and the second power supply.

6. The programmable circuit of claim 1, wherein the first power supply is approximately Vcc.

7. The programmable circuit of claim 1, wherein the first power supply is approximately Vcc/2.

8. The programmable circuit of claim 1, wherein the switch is a transistor.

9. An integrated circuit receiving n address bits and comprising:

primary circuit elements being selectable by binary values of the n address bits;

redundant circuit elements; and

match anti-fuse circuits corresponding to the redundant circuit elements, each match anti-fuse circuit comprising;

a plurality of programmable circuits, each being coupled to a first power supply and a second power supply and providing a programmed signal corresponding to one of the possible binary values of at least one of the n address bits, wherein each programmable circuit is responsive to a binary value of the at least one of the n address bits to activate the programmed signal when the binary value of the at least one of the n address bits corresponds to the programmed signal, each programmable circuit including;

a first node, wherein the state of the programmed signal is based on the state of the first node;

a first anti-fuse for selectively coupling the first node to a first power supply when in a programmed state and decoupling the first node from the first power supply when in an unprogrammed state;

a second anti-fuse for selectively coupling the first node to a second power supply when in a programmed state and decoupling the first node from the second power supply when in an unprogrammed state; and

a switch for selectively coupling the first node to the second power supply regardless of the state of the second anti-fuse; and

a compare circuit coupled to the plurality of programmable circuits for activating a match signal in response to all of the programmed signals being active, wherein the activated match signal is used to disable a primary circuit element from being selected by a corresponding binary value of the n address bits and to enable the redundant circuit element to be selected by the corresponding binary value of the n address bits.

10. The integrated circuit of claim 9, wherein the first power supply is approximately Vcc.

11. The integrated circuit of claim 9, wherein the first power supply is approximately Vcc/2.

12. The integrated circuit of claim 9, wherein the second power supply is a ground potential.

13. A programmable circuit for providing a programmed signal in an integrated circuit, comprising:

a first node, wherein the state of the programmed signal is based on the state of the first node;

a first anti-fuse for selectively coupling the first node to a first bus when in a programmed state and coupling the first node to a first power supply when in an unprogrammed state;

a second anti-fuse for selectively coupling the first node to a second bus when in a programmed state and coupling the first node to a ground when in an unprogrammed state; and

a switch for selectively coupling the first node to the second bus regardless of the state of the first and second anti-fuses.

14. The programmable circuit of claim 13, wherein the switch is a transistor.

15. A programmable circuit coupled to a first power supply and a second power supply for providing a programmed signal in an integrated circuit comprising:

a first node, wherein the state of the programmed signal is based on the state of the first node;

a first anti-fuse having a programmed state and an unprogrammed state and coupling the first node to the first power supply when in the programmed state and decoupling the first node from the first power supply when in the unprogrammed state, wherein the first anti-fuse has a first terminal coupled to the first node and a second terminal;

a second anti-fuse having a programmed state and an unprogrammed state and coupling the first node to the second power supply when in the programmed state and decoupling the first node from the second power supply when in the unprogrammed state, wherein the second anti-fuse has a first terminal coupled to the first node and a second terminal;

a first programming bus carrying a sufficient voltage to short the first anti-fuse;

a first switch coupled to the second terminal of the first anti-fuse for coupling the second terminal of the first anti-fuse to the first power supply during normal operation of the integrated circuit and coupling the second terminal of the first anti-fuse to the first programming bus during a first programming operation of the integrated circuit for programming the first anti-fuse;

a second programming bus carrying a sufficient voltage to short the second anti-fuse; and

a second switch coupled to the second terminal of the second anti-fuse for coupling the second terminal of the second anti-fuse to the second power supply during normal operation of the integrated circuit and coupling the second terminal of the second anti-fuse to the second programming bus during a second programming operation of the integrated circuit for programming the second anti-fuse.

16. The programmable circuit of claim 15, further comprising:

a third switch coupled between the second power supply and the first node and responsive to at least one programming control signal, wherein the switch is closed to couple the first node to the second power supply during a programming operation of the integrated circuit and open during normal operations of the integrated circuit.

17. The programmable circuit of claim 16, wherein the third switch comprises two transistors.

18. The programmable circuit of claim 15, further comprising:

a third switch coupled between the second power supply and the first node and responsive to an enable signal, wherein the switch is closed to couple the first node to the second power supply based on the enable signal being in a first state, and wherein the switch is open based on the enable signal being in a second state.

19. The programmable circuit of claim 18, wherein the switch comprises a transistor.

20. The programmable circuit of claim 15, wherein the second power supply comprises a ground node.

21. A programmable circuit for providing a programmed signal in an integrated circuit, comprising:

a first node, wherein the state of the programmed signal is based on the state of the first node;

a first anti-fuse having a first terminal and a second terminal and having a programmed state and an unprogrammed state, wherein the first terminal is coupled to the first node;

a second anti-fuse having a first terminal and a second terminal and having a programmed state and an unprogrammed state, wherein the first terminal is coupled to the first node;

a first programming bus carrying a sufficient voltage to short the first anti-fuse;

a first switch coupled to the second terminal of the first anti-fuse for coupling the second terminal of the first anti-fuse to a first power supply during normal operation of the integrated circuit and coupling the second terminal of the first anti-fuse to the first programming bus during a first programming operation of the integrated circuit for programming the first anti-fuse;

a second programming bus carrying a sufficient voltage to short the second anti-fuse; and

a second switch coupled to the second terminal of the second anti-fuse for coupling the second terminal of the second anti-fuse to a second power supply during normal operation of the programmable circuit and coupling the second terminal of the second anti-fuse to the second programing bus during a second programming operation of the programmable circuit for programming the second anti-fuse;

wherein the first anti-fuse couples the first node to the first power supply during normal operation when in the programmed state and decouples the first node from the first power supply when in the unprogrammed state; and

wherein the second anti-fuse couples the first node to the second power supply during normal operation when in the programmed state and decouples the first node from the second power supply when in the unprogrammed state.

22. The programmable circuit of claim 21, wherein the second power supply comprises a ground node.

23. A programmable circuit for providing a programmed signal in an integrated circuit, comprising:

a first node, wherein the state of the programmed signal is based on the state of the first node;

a first anti-fuse having a programmed state and an unprogrammed state and coupling the first node to a first power supply when in the programmed state and decoupling the first node from the first power supply when in the unprogrammed state;

a second anti-fuse having a programmed state and an unprogrammed state and coupling the first node to a second power supply when in the programmed state and decoupling the first node from the second power supply when in the unprogrammed state; and

a switch coupled between the second power supply and the first node, wherein the switch, when closed, couples the first node to the second power supply regardless of the state of the second anti-fuse.

24. The programmable circuit of claim 23, wherein the switch comprises a transistor.

25. A programmable circuit for providing a programmed signal in an integrated circuit, comprising:

a first node, wherein the state of the programmed signal is based on the state of the first node;

a first anti-fuse having a programmed state and an unprogrammed state and coupling the first node to a first power supply when in the programmed state and decoupling the first node from the first power supply when in the unprogrammed state;

a second anti-fuse having a programmed state and an unprogrammed state and coupling the first node to a second power supply when in the programmed state and decoupling the first node from the second power supply when in the unprogrammed state;

a first switch coupled between the second power supply and the first node and sponsive to at least one programming control signal, wherein the switch is closed to couple the first node to the second power supply during a programming operation of the integrated circuit regardless of the state of the second anti-fuse and open during normal operation of the integrated circuit; and

a second switch coupled between the second power supply and the first node and responsive to an enable signal, wherein the switch is closed to couple the first node to the second power supply based on the enable signal being in a first state regardless of the state of the second anti-fuse, and wherein the switch is open based on the enable signal being in a second state.

26. The programmable circuit of claim 25, wherein the first switch and second switch each comprise a transistor.

27. The programmable circuit of claim 25, wherein the second power supply comprises a ground node.

28. A programmable circuit coupled to a first power supply and a second power supply for providing a programmed signal in an integrated circuit comprising:

a first node, wherein the state of the programmed signal is based on the state of the first node;

a first anti-fuse having a programmed state and an unprogrammed state and connected for coupling the first node to the first power supply when in the programmed state and decoupling the first node from the first power supply when in the unprogrammed state, wherein the first anti-fuse has a first terminal coupled to the first node and a second terminal;

a second anti-fuse having a programmed state and an unprogrammed state and connected for coupling the first node to the second power supply when in the programmed state and decoupling the first node from the second power supply when in the unprogrammed state, wherein the second anti-fuse has a first terminal coupled to the first node and a second terminal;

a first programming bus carrying a sufficient voltage to short the first anti-fuse;

a first switch coupled to the second terminal of the first anti-fuse for coupling the second terminal of the first anti-fuse to the first power supply during normal operation of the integrated circuit and coupling the second terminal of the first anti-fuse to the first programing bus during a first programming operation of the integrated circuit for programming the first anti-fuse;

a second programming bus carrying a sufficient voltage to short the second anti-fuse;

a second switch coupled to the second terminal of the second anti-fuse for coupling the second terminal of the second anti-fuse to the second power supply during normal operation of the integrated circuit and coupling the second terminal of the second anti-fuse to the second programming bus during a second programming operation of the integrated circuit for programming the second anti-fuse; and

a transistor coupled between the second power supply and the first node and responsive to at least one programming control signal, wherein the switch is closed to couple the first node to the second power supply during a programming operation of the integrated circuit and open during normal operations of the integrated circuit.

29. The programmable circuit of claim 28, wherein the programming control signal is an enable signal.

30. The programmable circuit of claim 28, wherein the second power supply comprises a source of ground potential.

31. The programmable circuit of claim 30, wherein the first power supply has a voltage V_cc.

32. A programmable circuit coupled to a first power supply and a second power supply for providing a programmed signal in an integrated circuit comprising:

a first node, wherein the state of the programmed signal is based on the state of the first node;

a first anti-fuse having a programmed state and an unprogrammed state and connected for coupling the first node to the first power supply when in the programmed state and decoupling the first node from the first power supply when in the unprogrammed state, wherein the first anti-fuse has a first terminal coupled to the first node and a second terminal;

a second anti-fuse having a programmed state and an unprogrammed state and connected for coupling the first node to the second power supply when in the programmed state and decoupling the first node from the second power supply when in the unprogrammed state, wherein the second anti-fuse has a first terminal coupled to the first node and a second terminal;

a first programming bus carrying a sufficient voltage to short the first anti-fuse;

a first switch coupled to the second terminal of the first anti-fuse for coupling the second terminal of the first anti-fuse to the first power supply during normal operation of the integrated circuit and coupling the second terminal of the first anti-fuse to the first programming bus during a first programming operation of the integrated circuit for programming the first anti-fuse;

a second programming bus carrying a sufficient voltage to short the second anti-fuse; and

a second switch coupled to the second terminal of the second anti-fuse for coupling the second terminal of the second anti-fuse to the second power supply during normal operation of the integrated circuit and coupling the second terminal of the second anti-fuse to the second programing bus during a second programming operation of the integrated circuit for programming the second anti-fuse; and

a third switch comprising a transistor coupled between the second power supply and the first node and responsive to an enable signal, wherein the switch is closed to couple the first node to the second power supply based on the enable signal being in a first state, and wherein the switch is open based on the enable signal being in a second state.

33. The programmable circuit according to claim 32, wherein the second power supply comprises a source of ground potential.

34. The programmable circuit according to claim 32, wherein the first power supply has a voltage V_cc.

35. A programmable circuit for providing a programmed signal in an integrated circuit, comprising:

a first node, wherein the state of the programmed signal is based on the state of the first node;

a first anti-fuse for selectively coupling the first node to a first power supply when in a programmed state and decoupling the first node from the first power supply when in an unprogrammed state;

a second anti-fuse for selectively coupling the first node to a second power supply when in a programmed state and decoupling the first node from the second power supply when in an unprogrammed state; and

a switch for selectively coupling the first node to the second power supply regardless of the state of the first and second anti-fuses.

36. The programmable circuit of claim 35, wherein no long-L p-channel pull-up transistor is interposed between the first node and either power supply.

37. The programmable circuit of claim 35, wherein the second power supply is a ground potential.

38. An integrated circuit receiving n address bits and comprising:

primary circuit elements being selectable by binary values of the n address bits;

redundant circuit elements; and

match anti-fuse circuits corresponding to the redundant circuit elements, each match anti-fuse circuit comprising;

a plurality of programmable circuits, each being coupled to a first power supply and a second power supply and providing a programmed signal corresponding to one of the possible binary values of at least one of the n address bits, wherein each programmable circuit is responsive to a binary value of the at least one of the n address bits to activate the programmed signal when the binary value of the at least one of the n address bits corresponds to the programmed signal, each programmable circuit including;

a first node, wherein the state of the programmed signal is based on the state of the first node;

a first anti-fuse for selectively coupling the first node to a first power supply when in a programmed state and decoupling the first node from the first power supply when in an unprogrammed state;

a second anti-fuse for selectively coupling the first node to a second power supply when in a programmed state and decoupling the first node from the second power supply when in an unprogrammed state; and

a switch for selectively coupling the first node to the second power supply regardless of the state of the first and second anti-fuses; and

a compare circuit coupled to the plurality of programmable circuits for activating a match signal in response to all of the programmed signals being active, wherein the activate match signal is used to disable a primary circuit element from being selected by a corresponding binary value of the n address bits and to enable the redundant circuit element to be selected by the corresponding binary value of the n address bits.

39. The integrated circuit of claim 38, wherein the second power supply is a ground potential.

40. The integrated circuit of claim 38, wherein the first power supply is approximately Vcc.

41. The integrated circuit of claim 38, wherein the first power supply is approximately Vcc/2.

42. A programmable circuit for providing a programmed signal in an integrated circuit, comprising:

a first node, wherein the state of the programmed signal is based on the state of the first node;

a first anti-fuse for selectively coupling the first node to a first power supply when in a programmed state and decoupling the first node from the first power supply when in an unprogrammed state;

a second anti-fuse for selectively coupling the first node to a second power supply when in a programmed state and decoupling the first node from the second power supply when in an unprogrammed state; and

a transistor for selectively coupling the first node to the second power supply regardless of the state of the first and second anti-fuses.

43. The programmable circuit of claim 42, wherein the first power supply is approximately Vcc/2.

44. The programmable circuit of claim 42, wherein the second power supply is a ground potential.

45. The programmable circuit of claim 42, wherein no long-L p-channel pull-up transistor is interposed between the first node and the first power supply.

46. The programmable circuit of claim 42, wherein no long-L p-channel pull-up transistor is interposed between the first node and the second power supply.

47. The programmable circuit of claim 42, wherein no long-L p-channel pull-up transistor is interposed between the first node and both of the first power supply and the second power supply.

48. The programmable circuit of claim 42, wherein the first power supply is approximately Vcc.

49. An integrated circuit receiving n address bits and comprising:

primary circuit elements being selectable by binary values of the n address bits;

redundant circuit elements; and

match anti-fuse circuits corresponding to the redundant circuit elements, each match anti-fuse circuit comprising;

a plurality of programmable circuits, each being coupled to a first power supply and a second power supply and providing a programmed signal corresponding to one of the possible binary values of at least on of the n address bits, wherein each programmable circuit is responsive to a binary value of the at least one of the n address bits to activate the programmed signal when the binary value of the at least one of the n address bits corresponds to the programmed signal, each programmable circuit including;

a first node, wherein the state of the programmed signal is based on the state of the first node;

a first anti-fuse for selectively coupling the first node to a first power supply when in a programmed state and decoupling the first node from the first power supply when in an unprogrammed state;

a second anti-fuse for selectively coupling the first node to a second power supply when in a programmed state and decoupling the first node from the second power supply when in a unprogrammed state; and

a transistor for selectively coupling the first node to the second power supply regardless of the state of the first and second anti-fuses; and

a compare circuit coupled to the plurality of programmable circuits for activating a match signal in response to all of the programmed signals being active, wherein the activated match signal is used to disable a primary circuit element from being selected by a corresponding binary value of the n address bits and to enable the redundant circuit element to be selected by the corresponding binary value of the n address bits.

50. The integrated circuit of claim 49, wherein the second power supply is a ground potential.

51. The integrated circuit of claim 49, wherein the first power supply is approximately Vcc.

52. The integrated circuit of claim 49, wherein the fist power supply is approximately Vcc/2.

53. A programmable circuit for providing a programmed signal in an integrated circuit, comprising:

a first node, wherein the state of the programmed signal is based on the state of the first node;

a first anti-fuse for selectively coupling the first node to a first power supply when in a programmed state and decoupling the first node from the first power supply when in an unprogrammed state;

a second anti-fuse for selectively coupling the first node to a second power supply when in a programmed state and decoupling the first node from the second power supply when in an unprogrammed state; and

a switch for selectively coupling the first node to the second power supply regardless of the state of the first anti-fuse.

54. The programmable circuit of claim 53, wherein the switch is a transistor.

55. The programmable circuit of claim 53, wherein the second power supply is a ground potential.

56. The programmable circuit of claim 53, wherein no long-L p-channel pull-up transistor is interposed between the first node and the first power supply.

57. The programmable circuit of claim 53, wherein no long-L p-channel pull-up transistor is interposed between the first node and the second power supply.

58. The programmable circuit of claim 53, wherein no long-L p-channel pull-up transistor is interposed between the first node and both of the first power supply and the second power supply.

59. The programmable circuit of claim 53, wherein the first power supply is approximately Vcc.

60. The programmable circuit of claim 53, wherein the first power supply is approximately Vcc/2.

61. An integrated circuit receiving n address bits and comprising:

primary circuit elements being selectable by binary values of the n address bits;

redundant circuit elements; and

match anti-fuse circuits corresponding to the redundant circuit elements, each match anti-fuse circuit comprising;

a plurality of programmable circuits, each being coupled to a first power supply and a second power supply and providing a programmed signal corresponding to one of the possible binary values of at least one of the n address bits, wherein each programmable circuit is responsive to a binary value of the at least one of the n address bits to activate the programmed signal when the binary value of the at least one of the n address bits corresponds to the programmed signal, each programmable circuit including;

a first node, wherein the state of the programmed signal is based on the state of the first node;

a first anti-fuse for selectively coupling the first node to a first power supply when in a programmed state and decoupling the first node from the first power supply when in an unprogrammed state;

a second anti-fuse for selectively coupling the first node to a second power supply when in a programmed state and decoupling the first node from the second power supply when in an unprogrammed state; and

a switch for selectively coupling the first node to the second power supply regardless of the state of the first anti-fuse; and

a compare circuit coupled to the plurality of programmable circuits for activating a match signal in response to all of the programmed signals being active, wherein the activated match signal is used to disable a primary circuit element from being selected by a corresponding binary value of the n address bits and to enable the redundant circuit element to be selected by the corresponding binary value of the n address bits.

62. The integrated circuit of claim 61, wherein the second power supply is a ground potential.

63. The integrated circuit of claim 61, wherein the first power supply is approximately Vcc.

64. The integrated circuit of claim 61, wherein the fist power supply is approximately Vcc/2.

65. A programmable circuit for providing a programmed signal in an integrated circuit, comprising:

a first node, wherein the state of the programmed signal is based on the state of the first node;

a first anti-fuse having a first terminal and a second terminal and having a programmed state and an unprogrammed state, wherein the first terminal is coupled to the first node and couples the first node to the first power supply during normal operation when in the programmed state and decouples the first node from the first power supply when in the unprogrammed state;

a second anti-fuse having a first terminal and a second terminal and having a programmed state and an unprogrammed state, wherein the first terminal is coupled to the first node and couples the first node to the second power supply during normal operation when in the programmed state and decouples the first node from the second power supply when in the unprogrammed state;

a first programming bus carrying a sufficient voltage to short the first anti-fuse;

a first switch coupled to the second terminal of the first anti-fuse for selectively coupling the second terminal of the first anti-fuse to a first power supply during normal operation of the integrated circuit and coupling the second terminal of the first anti-fuse to the first programming bus during a first programming operation of the integrated circuit for programming the first anti-fuse;

a second programming bus carrying a sufficient voltage to short the second anti-fuse;

a second switch coupled to the second terminal of the second anti-fuse for selectively coupling the second terminal of the second anti-fuse to a second power supply during normal operation of the programmable circuit and coupling the second terminal of the second anti-fuse to the second programming bus during a second programming operation of the programmable circuit for programming the second anti-fuse; and

wherein only one of the first and second anti-fuses is in the programmed state during normal operation.

66. The programmable circuit according to claim 65, wherein the second power supply is a source of ground potential.

67. The programmable circuit according to claim 65, wherein the first power supply has a voltage V_cc.

68. A programmable circuit for providing a programmed signal in an integrated circuit, comprising:

a first node, wherein the state of the programmed signal is based on the state of the first node;

a first anti-fuse having a programmed state and an unprogrammed state and selectively coupling the first node to a first power supply when in the programmed state and decoupling the first node from the first power supply when in the unprogrammed state;

a second anti-fuse having a programmed state and an unprogrammed state and selectively coupling the first node to a second power supply when in the programmed state and decoupling the first node from the second power supply when in the unprogrammed state;

a first switch coupled between the second power supply and the first node and responsive to at least one programming control signal, wherein the switch is closed to couple the first node to the second power supply during a programming operation of the integrated circuit regardless of the state of the second anti-fuse and open during normal operation of the integrated circuit;

a second switch coupled between the second power supply and the first node and responsive to an enable signal, wherein the switch is closed to couple the first node to the second power supply based on the enable signal being in a first state regardless of the state of the second anti-fuse, and wherein the switch is open based on the enable signal being in a second state; and

wherein the only one of the first and second anti-fuses is put in the programmed state at the same time.

69. The programmable circuit according to claim 68, wherein the second power supply is a source of ground potential.

70. The programmable circuit according to claim 69, wherein the fist power supply has a voltage V_cc.