Circuit for cancelling and replacing redundant elements
AssigneeMicron Technology, Inc.
InventorsPaul S. Zagar, Adrian E. Ong
Life of this patent
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Abstract
In an integrated circuit having addressable primary elements and redundant elements which can be programmed to replace primary elements, a circuit and method are provided for cancelling and replacing redundant elements. A circuit is described which can be used in a memory such as a dynamic random access memory (DRAM) which uses a selectively blowable anti-fuse to disable a redundant element which was previously programmed to replace a defective primary element. The disclosure describes a method for permanently cancelling the defective redundant element and replacing the defective redundant element with another redundant element.
Claims13
A method of repairing a integrated circuit comprising the steps of;
- one time addressing a redundant element;
- determining that the redundant element is defective;
- and
- selectively blowing an anti-fuse circuit to permanently disable the defective redundant element.
A method of repairing an integrated circuit comprising a plurality of selectively programmable redundant elements wherein a first one of the plurality of selectively programmable redundant elements is one time programmed, the method comprising the step of;
- permanently replacing the first one of the plurality of selectively programed redundant elements with a second one of the plurality of selectively programmable redundant elements after the one time programming.
A method of canceling an enabled defective redundant element, comprising:
- one time addressing the defective redundant element and identifying the redundant element is defective;
- and
- selectively blowing an anti-fuse circuit to permanently disable the defective redundant element.
A method of repairing an integrated circuit comprising a plurality of selectively programmable redundant elements, the method comprising:
- one time enabling a first one of the plurality of selectively programmable redundant elements;
- and
- permanently replacing the first one of the plurality of selectively programmable redundant elements with a second one of the plurality of selectively programmable redundant elements.
A method of repairing a memory circuit, comprising:
- identifying a defective primary memory element of the memory circuit, wherein the defective primary memory element has an address;
- one time selecting a first redundant memory element to replace the defective primary memory element;
- one time programming the first redundant memory element to respond to the address of the defective primary memory element;
- identifying the first redundant memory element as defective after the one time programming;
- selecting a second redundant memory element to replace the first redundant memory element;
- programming the second redundant memory element to respond to the address of the defective primary memory element;
- and
- permanently disabling the first redundant memory element.
A method of repairing a memory circuit, comprising:
- identifying a defective primary memory element of the memory circuit, wherein the defective primary memory element has an address;
- one time selecting a first redundant memory element to replace the defective primary memory element;
- one time programming the first redundant memory element to respond to the address of the defective primary memory element;
- identifying the first redundant memory element as defective after the one time programming;
- addressing the first redundant memory element;
- selectively blowing an anti-fuse circuit to permanently disable the first redundant memory element;
- selecting a second redundant memory element to replace the first redundant memory element;
- and
- programming the second redundant memory element to respond to the address of the defective primary memory element.
A method of repairing a memory circuit, comprising:
- identifying a defective primary row of the memory circuit, wherein the defective primary row has an address;
- one time selecting a first redundant row to replace the defective primary row;
- one time programming the first redundant row to respond to the address of the defective primary row;
- identifying the first redundant row as defective after the one time programming;
- addressing the first redundant row;
- selectively blowing an anti-fuse circuit to permanently disable the first redundant row;
- selecting a second redundant row to replace the first redundant row;
- and
- programming the second redundant row to respond to the address of the defective primary row.
A method of repairing an integrated circuit having a defective selectively addressable primary element, the method comprising:
- one time selecting a first selectively programmable redundant element to replace the defective selectively addressable primary element;
- one time programming the first selectively programmable redundant element to respond to an address of the defective selectively addressable primary element;
- identifying the first selectively programmable redundant element as defective after the one time programming;
- selecting a second selectively programmable redundant element to replace the first selectively programmable redundant element;
- programming the second selectively programmable redundant element to respond to the address of the defective selectively addressable primary element;
- and
- permanently disabling the first selectively programmable redundant element.
A method of repairing an integrated circuit having a defective selectively addressable primary element, the method comprising:
- one time selecting a first selectively programmable redundant element to replace the defective selectively addressable primary element;
- one time programming the first selectively programmable redundant element to respond to the address of the defective selectively addressable primary element;
- identifying the first selectively programmable redundant element as defective after the one time programming;
- addressing the first selectively programmable redundant element;
- selectively blowing an anti-fuse circuit to permanently disable the first selectively programmable redundant element;
- selecting a second selectively programmable redundant element to replace the first redundant element;
- and
- programming the second selectively programmable redundant element to respond to the address of the defective selectively addressable primary element.
Dependencies are inferred from the claim text.