Method compensation operating voltage, flash memory device, and data storage device

• US 8,659,966 B2
• Filed: 09/19/2011
• Issued: 02/25/2014
• Est. Priority Date: 11/25/2010
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Choi, Yoon Hee, Park, Ki Tae, Kim, Bo Geun
• Primary Examiner(s): DINH, SON T
• Application Number:
  US13/235,695
• Publication Number:
  US 20120134213A1
• Time in Patent Office: 890 Days
• Field of Search: 365/211, 365/185.18, 365/185.2
• US Class Current: 365/211
• CPC Class Codes: G11C 16/10 Programming or data input circuits
• CPC Class Codes: G11C 16/26 Sensing or reading circuits; Data output circuits
• CPC Class Codes: G11C 16/30 Power supply circuits
• CPC Class Codes: G11C 7/04 with means for avoiding disturbances due to temperature effects

Abstract

Disclosed is a method generating a compensated operating voltage, such as a read voltage, in a non-volatile memory device, and a related non-volatile memory device. The operating voltage is compensated in response to one or more memory cell conditions such as temperature variation, programmed data state or physical location of a selected memory cell, page information for selected memory cell, or the location of a selected word line.

Claims

1. A method generating an operating voltage in a non-volatile memory device including a memory cell array of non-volatile memory cells, the method comprising:

detecting at least one memory cell condition including a current temperature for the non-volatile memory device;

generating the operating voltage to be applied to a selected memory cell in the memory cell array; and

compensating the operating voltage in response to the at least one memory cell condition,

wherein the at least one memory cell condition includes in addition to the current temperature at least one of a programmed data state of the selected memory cell, a location of the selected memory cell in the memory cell array, page information associated with the selected memory cell, and a location of a selected word line associated with the selected memory cell in the memory cell array.

2. The method of claim 1, wherein the at least one memory cell condition comprises a plurality of temperature ranges extending over a permissible temperature operating range for the non-volatile memory device, and

compensating the operating voltage comprises:

respectively assigning a different one of a plurality of compensating shifts to each one of the plurality of temperature ranges;

determining a current temperature range among the plurality of temperature ranges that includes the current temperature; and

applying one of the plurality of compensating shifts to the operating voltage that corresponds to the current temperature range.

3. The method of claim 2, wherein the operating voltage is one of a read voltage used to discriminate a threshold voltage distribution for the selected memory cell during a read operation performed by the non-volatile memory device, and a read verification voltage used to discriminate a threshold voltage distribution for the selected memory cell during a program operation performed by the non-volatile memory device.

4. The method of claim 1, wherein the selected memory cell is configured to be programmed according to a first program state and a second program state,

the at least one memory cell condition comprises a temperature range including the current temperature and the programmed state of the selected memory cell, and

compensating the operating voltage comprises:

applying a first compensating shift to the operating voltage when the selected memory cell is programmed to the first programmed state; and

applying a second compensating shift different from the first compensating shift to the operating voltage when the selected memory cell is programmed to the second programmed state.

5. The method of claim 4, wherein the operating voltage is one of a read voltage used to discriminate a threshold voltage distribution for the selected memory cell during a read operation performed by the non-volatile memory device, and a read verification voltage used to discriminate a threshold voltage distribution for the selected memory cell during a program operation performed by the non-volatile memory device.

6. The method of claim 1, wherein the selected memory cell is one of a first memory cell associated with a first word line of the memory cell array and a second memory cell associated with a second word line of the memory cell array,

the at least one memory cell condition comprises the location of the selected word line in the memory cell array, and

compensating the operating voltage comprises:

if the selected memory cell is the first memory cell, applying a first compensating shift to the operating voltage corresponding to a location of the first word line in the memory cell array; and

if the selected memory cell is the second memory cell, applying a second compensating shift different from the first compensating shift to the operating voltage corresponding to a location of the second word line in the memory cell array.

7. The method of claim 6, wherein the operating voltage is one of a read voltage used to discriminate a threshold voltage distribution for the selected memory cell during a read operation performed by the non-volatile memory device, and a read verification voltage used to discriminate a threshold voltage distribution for the selected memory cell during a program operation performed by the non-volatile memory device.

8. The method of claim 1, wherein the at least one memory cell condition includes;

a plurality of temperature ranges extending over a permissible temperature operating range for the non-volatile memory device, the programmed data state for the selected memory cell, and the location of a selected word line in the memory cell array, and

compensating the operating voltage comprises;

applying a first compensating shift to the operating voltage in view of a current temperature range among the plurality of temperature ranges that includes the current temperature;

applying a second compensating shift to the operating voltage in view of the programmed state of the selected memory cell; and

applying a third compensating shift to the operating voltage in view of the location of the selected word line in the memory cell array.

9. The method of claim 8, wherein the first compensating shift, second compensating shift and third compensating shift are sequentially applied to the operating voltage.

10. The method of claim 8, wherein the first compensating shift, second compensating shift and third compensating shift are simultaneously applied to the operating voltage.

11. A method generating an operating voltage in a memory system comprising a non-volatile memory device including an operating voltage generator, and a memory cell array of non-volatile memory cells, the method comprising:

storing trim information in a trim information region of the memory cell array, wherein the trim information comprises voltage trim information;

upon powering-up the non-volatile memory device and using the trim voltage information, configuring at least one lookup table storing a plurality of compensating offset values;

detecting a current temperature for the non-volatile memory device;

after receiving an access command initiating execution of an access operation by the non-volatile memory device, generating a compensated operating voltage by selecting an offset value from the plurality of compensating offset values stored in the at least one lookup table in response to the current temperature; and

performing the access operation using the compensated operating voltage.

12. The method of claim 11, wherein generating the compensated operating voltage comprises:

using the operating voltage generator to generate a nominal operating voltage; and

adjusting the nominal operating voltage in response to the selected offset value.

13. The method of claim 12, wherein selecting the offset value from the plurality of compensating offset values comprises:

selecting a first offset value from the plurality of offset values in response to the current temperature, and selecting a second offset value from the plurality of offset values in response to a memory cell condition; and

adjusting the nominal operating voltage in response to the selected offset value comprises sequentially adjusting the nominal operating voltage in response to first offset value and the second offset value.

14. The method of claim 13, wherein the memory cell condition is at least one condition selected from a group comprising:

a programmed data state for a selected memory cell in the memory cell array, a location of a selected word line associated with the selected memory cell within the memory cell array, page information associated with the selected memory cell, and a location of the selected memory cell within the memory cell array.

15. The method of claim 11, wherein generating the compensated operating voltage comprises:

generating a compensating offset value using the selected offset value; and

using the operating voltage generator to generate the compensated operating voltage in response to the compensating offset value.

16. The method of claim 15, wherein generating the compensating offset value comprises:

selecting a first offset value from the plurality of offset values in response to the current temperature;

selecting a second offset value from the plurality of offset values in response to a memory cell condition; and

combining the first offset value and the second offset value to generate the compensating offset value.

17. The method of claim 16, wherein the memory cell condition is at least one condition selected from a group comprising:

a programmed data state for a selected memory cell in the memory cell array, a location of a selected word line associated with the selected memory cell within the memory cell array, page information associated with the selected memory cell, and a location of the selected memory cell within the memory cell array.

18. The method of claim 11, wherein the at least one lookup table comprises:

a first lookup table storing a plurality first offset values respectively corresponding to a plurality of temperature ranges; and

a second lookup table storing a plurality second offset values respectively corresponding to variations in a memory cell condition.

19. The method of claim 18, wherein the memory cell condition is one condition selected from a group consisting of:

a programmed data state for a selected memory cell in the memory cell array, a location of a selected word line associated with the selected memory cell within the memory cell array, and a location of the selected memory cell within the memory cell array.

20. A non-volatile memory device comprising:

control logic that controls operation of the non-volatile memory device;

a memory cell array of nonvolatile memory cells; and

an operating voltage generator that generates a compensated operating voltage to be applied to a selected memory cell in the memory cell array, wherein the operating voltage generator comprises;

a temperature code generator that detects a current temperature and generates a corresponding temperature code;

a first lookup table that stores a plurality of first offset values that respectively correspond to a plurality of temperature ranges; and

a second lookup table that stores a plurality of second offset values that respectively correspond to variations in a memory cell condition,

wherein the control logic selects one of the first offset values in response to the temperature code and one of the second offset values in response to a determined variation in the memory cell condition, and

the operating voltage generator generates the compensated operating voltage in response to the first offset value and the second offset value.

21. The non-volatile memory device of claim 20, wherein the variations in the memory cell condition respectively correspond to programmed data states for the selected memory cell.

22. The non-volatile memory device of claim 20, wherein the variations in the memory cell condition respectively correspond to locations of at least one word line in the memory cell array associated the selected memory cell.

23. The non-volatile memory device of claim 20, wherein the variations in the memory cell condition respectively correspond to page information associated with the selected memory cell.

24. The non-volatile memory device of claim 20, wherein the variations in the memory cell condition respectively correspond to locations of the selected memory cell within the memory cell array.

25. The non-volatile memory device of claim 20, wherein the operating voltage is one of a read voltage used to discriminate a threshold voltage distribution for the selected memory cell during a read operation performed by the non-volatile memory device, and a read verification voltage used to discriminate a threshold voltage distribution for the selected memory cell during a program operation performed by the non-volatile memory device.

26. The non-volatile memory device of claim 20, wherein the control logic selects the one of the second offset values in further response to the temperature code.

27. A memory card comprising:

at least one non-volatile memory device;

a controller including a buffer memory and configured to control the non-volatile memory device; and

an interface providing an interface between the controller and an external device,

wherein the at least one non-volatile memory device comprises;

control logic that controls operation of the non-volatile memory device;

a memory cell array of nonvolatile memory cells; and

an operating voltage generator that generates a compensated operating voltage to be applied to a selected memory cell in the memory cell array, wherein the operating voltage generator comprises;

a temperature code generator that detects a current temperature and generates a corresponding temperature code;

a first lookup table that stores a plurality of first offset values that respectively correspond to a plurality of temperature ranges; and

a second lookup table that stores a plurality of second offset values that respectively correspond to variations in a memory cell condition,

wherein the control logic selects one of the first offset values in response to the temperature code and one of the second offset values in response to a determined variation in the memory cell condition, and

the operating voltage generator generates the compensated operating voltage in response to the first offset value and the second offset value.

28. A solid state drive (SSD) comprising:

storage media including a plurality of non-volatile memory devices; and

a controller connected with the storage media via a plurality of channels and configured to control the storage media,

wherein at least one of the plurality of non-volatile memory devices comprises;

control logic that controls operation of the non-volatile memory device;

a memory cell array of nonvolatile memory cells; and

an operating voltage generator that generates a compensated operating voltage to be applied to a selected memory cell in the memory cell array, wherein the operating voltage generator comprises;

a temperature code generator that detects a current temperature and generates a corresponding temperature code;

a first lookup table that stores a plurality of first offset values that respectively correspond to a plurality of temperature ranges; and

a second lookup table that stores a plurality of second offset values that respectively correspond to variations in a memory cell condition,

wherein the control logic selects one of the first offset values in response to the temperature code and one of the second offset values in response to a determined variation in the memory cell condition, and

the operating voltage generator generates the compensated operating voltage in response to the first offset value and the second offset value.

29. A method generating an operating voltage in a non-volatile memory device including a memory cell array of non-volatile memory cells, the method comprising:

detecting a programmed data state of a selected memory cell in the memory cell array;

generating the operating voltage to be applied to the selected memory cell; and

compensating the operating voltage in response to a read voltage level corresponding to the programmed data state of the selected memory cell.

30. A method generating an operating voltage in a non-volatile memory device including a memory cell array of non-volatile memory cells, the method comprising:

detecting a location of a selected word line in the memory cell array;

generating the operating voltage to be applied to the selected word line; and

compensating the operating voltage in response to the location of the selected word line.

31. A method generating an operating voltage in a non-volatile memory device including a memory cell array of non-volatile memory cells, the method comprising:

detecting a programmed data state of a selected memory cell in the memory cell array;

generating a read voltage to be applied to a selected word line associated with the selected memory cell in the memory cell array; and

compensating the read voltage in response to a read voltage level corresponding to the programmed data state of the selected memory cell.