Method for detecting or repairing intercell defects in more than one array of a memory device

• US 6,510,533 B1
• Filed: 12/26/2000
• Issued: 01/21/2003
• Est. Priority Date: 03/24/1998
• Status: Expired due to Term

• Current Assignee: Conversant Intellectual Property Management Inc (MOSAID Technologies Inc. (f/k/a Conversant Intellectual Property Management))
• Original Assignee: Micron Technology, Inc.
• Inventors: Siek, David D., Damon, Tim G.
• Primary Examiner(s): Ton, David
• Assistant Examiner(s): LAMARRE, GUY J
• Application Number:
  US09/749,854
• Time in Patent Office: 756 Days
• Field of Search: 714/718-720, 257/296, 257/313, 327/51, 365/200-202, 365/203, 365/307, 365/149, 365/233, 365/189.05, 365/190
• US Class Current: 714/719
• CPC Class Codes: G11C 11/401 forming cells needing refreshing or charge regeneration, i.e. dynamic cells
• CPC Class Codes: G11C 29/02 Detection or location of defective auxiliary circuits, e.g. defective refresh counters
• CPC Class Codes: G11C 29/26 Accessing multiple arrays G11C29/24 takes precedence
• CPC Class Codes: G11C 29/50 Marginal testing, e.g. race, voltage or current testing

Abstract

A method of testing and/or repairing a memory device having two arrays of memory cells arranged in rows and columns. Sense amplifiers shared by the arrays are selectively coupled by isolation transistors to the digit lines of respective columns in each array. The sense amplifiers and isolation transistors are controlled to sequentially writing known data bits to a plurality of rows in each of the arrays. The rows in the first and second arrays remain activated for a testing interval of sufficient duration to allow charge to transfer through any inter-cell defects between the cells in the activated rows and cells that are not in an activated row. Cells in each non-activated row are then read. Inter-cell defects may also be repaired by activating the rows in the first and second arrays in a manner that couples adjacent memory cells to digit lines having different complimentary voltages.

Claims

1. A method of establishing digit line voltages in a memory device having a plurality of memory arrays, comprising:

applying voltages to a first set of memory cells in a first of the arrays;

producing sense amplifier voltages by coupling respective sense amplifiers to memory cells in the first set through respective pairs of complimentary digit lines; and

using the sense amplifiers that produced the sense amplifier voltages to apply the produced sense amplifier voltages to memory cells in a second of the arrays through respective pairs of complimentary digit lines.

2. The method of claim 1, further comprising the act of isolating the sense amplifiers from the digit lines in the second array while producing the sense amplifier voltages.

3. The method of claim 1 wherein the act of applying voltages to a first set of memory cells in the first array comprises:

reading a memory cell coupled to each of a plurality of sense amplifiers to cause the sense amplifiers to generate predetermined sense amplifier voltages; and

coupling a plurality of memory cells to each of a plurality of the sense amplifiers that are generating the predetermined sense amplifier voltages.

4. The method of claim 1 wherein the act of producing the sense amplifier voltages comprises:

equilibrating the digit line voltages in the first array;

coupling the first set of cells to the digit lines in the first array; and

after coupling the first set of cells to the digit lines in the first array, sensing changes in the digit line voltages in the first array with the sense amplifiers.

5. The method of claim 1, further comprising the act of coupling a second set of cells in the first array to the digit lines in the first array after the act of producing sense amplifier voltages.

6. The method of claim 5, further including the act of coupling a third set of cells in the second array to the digit lines in the second array after the act of producing sense amplifier voltages by coupling sense amplifiers to memory cells in the first set.

7. The method of claim 6 wherein the act of coupling the third set of cells in the second array to the digit lines in the second bank precedes the act of coupling the second set of cells in the first array to the digit lines in the first array.

8. The method of claim 6 wherein the act of coupling the third set of cells in the second array to the digit lines in the second array follows the act of coupling the second set of cells in the first array to the digit lines in the first array.

9. The method of claim 1, wherein the memory device comprises a dynamic random access memory device, and wherein the memory cells in the arrays comprises dynamic random access memory cells.

10. A method of establishing digit line voltages in a memory device having a plurality of memory arrays, comprising:

writing data bits to a first set of memory cells in a first of the arrays;

reading data bits from the memory cells in the first set through respective pairs of complimentary digit lines using respective sense amplifiers coupled to the memory cells through the pairs of complimentary digit lines so that the sense amplifier output voltages corresponding to the read data bits; and

writing data bits to memory cells in a second of the arrays by coupling the sense amplifiers to respective memory cells in the second array through respective pairs of complimentary digit lines while the sense amplifiers are outputting the voltages corresponding to the read data bits.

11. The method of claim 10, further comprising the act of isolating the sense amplifiers from the digit lines in the second array while reading data bits from the memory cells in the first set.

12. The method of claim 10 wherein the act of writing data bits to a first set of memory cells in the first array comprises:

reading a memory cell coupled to each of a plurality of sense amplifiers to cause the sense amplifiers to generate predetermined sense amplifier voltages; and

coupling a plurality of memory cells to each of a plurality of the sense amplifiers that are generating the predetermined sense amplifier voltages.

13. The method of claim 10 wherein the act of reading data bits from the memory cells in the first set comprises:

equilibrating the digit line voltages in the first array;

coupling the first set of cells to the digit lines in the first array; and

after coupling the first set of cells to the digit lines in the first array, sensing changes in the digit line voltages in the first array with the sense amplifiers.

14. The method of claim 10, further comprising the act of coupling a second set of cells in the first array to the digit lines in the first array after the act of reading data bits from the memory cells in the first set.

15. The method of claim 14, further including the act of coupling a third set of cells in the second array to the digit lines in the second array after the act of reading data bits from the memory cells in the first set.

16. The method of claim 15 wherein the act of coupling the third set of cells in the second array to the digit lines in the second bank precedes the act of coupling the second set of cells in the first array to the digit lines in the first array.

17. The method of claim 14 wherein the act of coupling the third set of cells in the second array to the digit lines in the second array follows the act of coupling the second set of cells in the first array to the digit lines in the first array.

18. The method of claim 10, wherein the memory device comprises a dynamic random access memory device, and wherein the memory cells in the arrays comprises dynamic random access memory cells.