Memory system with a layer comprising a dedicated redundancy area
View Patent ↗Systems and methods are disclosed that may include a first layer comprising a first redundant memory element, an input/output interface, a first layer fuse box, and a fuse blowing control. These systems and methods also may include a second layer coupled to the first layer through a first connection comprising a second layer memory element and a second layer fuse box coupled to the first redundant memory element. In addition, these systems and methods may further include a redundancy register coupled to the first layer, wherein upon the failure of part of the second layer memory element, the redundancy register provides information to the fuse blowing control that allocates part of the first redundant memory element to provide redundancy for the failed part of the second layer memory element by blowing elements in the first layer fuse box and the second layer fuse box.
1. A system, comprising:
a first layer comprising a first redundant memory element, an input/output interface, a first layer fuse box, and a fuse blowing control;
a second layer coupled to the first layer through a first connection comprising a second layer memory element and a second layer fuse box coupled to the first redundant memory element; and
a redundancy register coupled to the first layer, wherein upon the failure of part of the second layer memory element, the redundancy register provides information to the fuse blowing control that allocates part of the first redundant memory element to provide redundancy for the failed part of the second layer memory element by blowing elements in the first layer fuse box and the second layer fuse box.
2. The system of claim 1 , wherein the first layer further comprises a first layer memory element.
3. The system of claim 2 , wherein the first redundant memory element comprises column redundant memory and row redundant memory.
4. The system of claim 1 , wherein the connection is a through silicon vias (TSV) connection.
5. The system of claim 2 , further comprising a third layer coupled to the first layer through the second layer, wherein the third layer comprises a third layer memory element and a third layer fuse box coupled to the first redundant memory element.
6. The system of claim 5 , further comprising a fourth layer coupled to the first layer, wherein the fourth layer comprises a fourth layer memory element and a fourth layer fuse box coupled to the first redundant memory element.
7. The system of claim 6 , comprising a fifth layer coupled to the first layer through a second connection, wherein the fifth layer comprises a fifth layer memory element and a fifth fuse box coupled to the first redundant memory element through a second connection.
8. The system of claim 5 , wherein the input/output interface is coupled to a layer comprising a second redundant memory element, a second input/output interface, and a second fuse blowing control.
9. The system of claim 1 , wherein the second layer further comprises a redundant memory element.
10. A method, comprising:
verifying a plurality of memory cells located across at least three layers of semiconductor material comprising memory cells;
determining the location of faults within the at least three layers of semiconductor material comprising memory cells;
assigning a type to each of the faults within the at least three layers of semiconductor material comprising memory cells;
determining if the chip is repairable based upon the location and type of faults based upon the faults of at least two of the three layers being repairable by one of the layers; and
storing repair information on one of the layers.
11. The method of claim 10 , further comprising:
allocating space on one of the layers to provide redundancy for faults located on at least two layers.
12. The method of claim 11 , wherein the repair information comprises row addresses, column address, a valid bit, and two tag bits.
13. The method of claim 12 , wherein the two tag bits are used to represent the type of fault, and wherein the type of fault is selected from the group: a row, column, or single fault.
14. The method of claim 11 , wherein the repair information is stored in a redundancy register.
15. The method of claim 11 , wherein the allocation is preformed by blowing at least one fuse in a fuse box.
16. The method of claim 11 , wherein the allocation comprises reading all repair information, and in a first iteration assigning redundancy for column and row failures and in a second iteration assigning redundancy for single failures.