Apparatuses, integrated circuits, and methods for measuring leakage current

• US 9,183,948 B2
• Filed: 10/14/2014
• Issued: 11/10/2015
• Est. Priority Date: 10/26/2011
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Yamada, Shigekazu
• Primary Examiner(s): MAI, SON LUU
• Application Number:
  US14/514,218
• Publication Number:
  US 20150029802A1
• Time in Patent Office: 392 Days
• Field of Search: 365/201
• US Class Current: 1/1
• CPC Class Codes: G11C 2029/1202 Word line control
• CPC Class Codes: G11C 2029/5006 Current
• CPC Class Codes: G11C 29/025 in signal lines
• CPC Class Codes: G11C 8/08 Word line control circuits, e.g. drivers, boosters, pull-up circuits, pull-down circuits, precharging circuits, for word lines

Abstract

Methods, apparatuses, and integrated circuits for measuring leakage current are disclosed. In one such example method, a word line is charged to a first voltage, and a measurement node is charged to a second voltage, the second voltage being less than the first voltage. The measurement node is proportionally coupled to the word line. A voltage on the measurement node is compared with a reference voltage. A signal is generated, the signal being indicative of the comparison. Whether a leakage current of the word line is acceptable or not can be determined based on the signal.

Claims

1. An apparatus, comprising:

a word line leakage measurement system coupled to word lines of a memory, the word line leakage measurement system configured to determine whether a level of leakage on a word line exceeds a threshold after compensating for noise encountered on a measurement node.

2. The apparatus of claim 1, further comprising a state machine coupled to the word line leakage measurement system and configured to control a series of leakage tests.

3. The apparatus of claim 2, wherein results of the series of leakage tests are provided to the word line leakage measurement system to determine whether the level of leakage on a word line exceeds a threshold.

4. The apparatus of claim 3, wherein the series of leakage tests are run automatically.

5. The apparatus of claim 1, wherein the word line leakage measurement system is internal to the memory.

6. The apparatus of claim 1, further comprising an input/output node coupled to the word line leakage measurement system.

7. The apparatus of claim 6, wherein results of determining whether a level of leakage on a word line exceeds a threshold are accessible externally through the input/output node.

8. The apparatus of claim 7, wherein the word line leakage measurement system further includes a capacitive voltage divider coupled to the measurement node.

9. The apparatus of claim 7, wherein the word line leakage measurement system further includes a proportioning circuit coupled to the measurement node, wherein the proportioning circuit is configured to proportion a voltage on a word line to a voltage on the measurement node.

10. A method, comprising:

determining a level of leakage on a word line;

compensating for noise on the word line; and

indicating whether the level of leakage on the word line exceeds a threshold after compensating for noise on a measurement node.

11. The method of claim 10, wherein the noise on the measurement node is introduced by a switch transitioning from being conductive to non-conductive.

12. The method of claim 11, wherein compensating for noise comprises compensating for a decrease in voltage due to the switch transition.

13. The method of claim 10, wherein compensating for noise on the measurement node comprises transitioning a compensation switch from non-conductive to conductive.

14. The method of claim 10, further comprising:

generating a signal indicating failing a word line leakage test responsive to the leakage on the word line exceeding the threshold.

15. The method of claim 10, further comprising:

capacitively coupling the word line to the measurement node; and

capacitively coupling the measurement node to ground.

16. The method of claim 10, further comprising:

decoupling the word line from a first voltage source; and

decoupling the measurement node from a second voltage source.

17. The method of claim 10, wherein determining a level of leakage on a word line further comprises comparing a voltage on the measurement node with a reference voltage.

18. The method of claim 10, further comprising:

decoupling an adjacent word line at ground concurrently with decoupling the word line from a first voltage source.

19. The method of claim 10, wherein the noise on the measurement node is introduced by decoupling the measurement node from a voltage source.

20. The method of claim 10, further comprising:

determining levels of leakage on other word lines;

indicating whether respective levels of leakage on the other word lines exceed a threshold after compensating for noise on the other word lines.