MEMORY DEVICES SUPPORTING SIMULTANEOUS PROGRAMMING OF MULTIPLE CELLS AND PROGRAMMING METHODS THEREOF

• US 20110013458A1
• Filed: 07/19/2010
• Published: 01/20/2011
• Est. Priority Date: 07/20/2009
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Seol, KwangSoo
• Granted Patent: US 8,385,131 B2
• Time in Patent Office: Days
• US Class Current: 365/185.18
• CPC Class Codes: G11C 16/0483 comprising cells having several storage transistors connected in series
• CPC Class Codes: G11C 16/10 Programming or data input circuits
• CPC Class Codes: H10B 41/20 characterised by three-dimensional arrangements, e.g. with cells on different height levels
• CPC Class Codes: H10B 41/27 the channels comprising vertical portions, e.g. U-shaped channels
• CPC Class Codes: H10B 43/20 characterised by three-dimensional arrangements, e.g. with cells on different height levels

Abstract

Some embodiments of the present invention provide methods of programming memory devices that include an array of vertical channels passing through a stacked plurality of word plates, wherein respective columns of vertical channels are configured to be coupled to respective bit lines. In some method embodiments, potentials of the vertical channels are boosted, followed by selectively applying respective data to vertical channels via the bit lines to thereby selectively change the potentials of the vertical channels according to the data. A program voltage is subsequently applied to a selected word plate to thereby program a plurality of cells.

Claims

1. A method of programming a memory device comprising an array of vertical channels passing through a stacked plurality of word plates, wherein respective columns of vertical channels are configured to be coupled to respective bit lines, the method comprising:

boosting potentials of the vertical channels;

selectively applying respective data to vertical channels via the bit lines to thereby selectively change the potentials of the vertical channels according to the data; and

applying a program voltage to a selected word plate to thereby program a plurality of memory cells.

2. The method of claim 1:

wherein respective memory cell strings are configured to be coupled to respective bit lines by respective groups of select gates;

wherein boosting potentials of the vertical channels comprises applying a first voltage to first ends of the memory cells strings while applying a second voltage greater than the first voltage to the plurality of word plates to thereby boost the potentials of the vertical channels;

wherein selectively applying respective data to vertical channels via the bit lines to thereby selectively change the potentials of the vertical channels according to the data comprises selectively driving respective ones of the select gates while applying respective data to the bit lines to thereby selectively change the potentials of the vertical channels according to the data; and

wherein applying a program voltage to a selected word plate to thereby program a plurality of memory cells comprises applying a third voltage to the selected word plate to thereby program a plurality of memory cells associated with the selected word plate.

3. The method of claim 2, wherein the select gates comprise upper select gales that control connection of the bit line to the column of vertical channels, wherein the memory device further comprises lower select gates that control connection of the vertical channels to a source plate and wherein applying a first voltage to first ends of memory cell strings while applying a second voltage to the plurality of word plates to boost potentials of the column of vertical channels comprises deactivating the upper select gates while applying the first voltage to the lower select gates and the source plate and applying the second voltage to the plurality of word plates.

4. The method of claim 3, wherein applying a first voltage to first ends of memory cell strings while applying a second voltage to the plurality of word plates to boost potentials of the column of vertical channels further comprises applying the first voltage to at least one of the bit lines while applying the first voltage to the lower select gates and the source plate and applying the second voltage to the plurality of word plates

5. The method of claim 2, wherein the select gates comprise upper select gates that control connection of the bit line to the column of vertical channels, wherein the memory device further comprises lower select gates that control connection of the column of vertical channels to a source plate and wherein applying a first voltage to first ends of memory cell strings while applying a second voltage to the plurality of word plates to boost potentials of vertical channels of the column of vertical channels comprises deactivating the lower select gates while applying the first voltage to the upper select gates and the bit line and applying the second voltage to the plurality of word plates.

6. The method of claim 5, wherein applying a first voltage to first ends of memory cell strings while applying a second voltage to the plurality of word plates to boost potentials of the column of vertical channels further comprises applying a fourth voltage less than the first voltage to the source plate while applying the first voltage to the upper select gates and the bit line and applying the second voltage to the plurality of word plates.

7. The method of claim 2, wherein applying a third voltage to a selected word plate to thereby program a plurality of memory cells associated with the column of vertical channels and the selected word plate comprises applying the third voltage to the selected word plate while applying a fourth voltage less than the third voltage to at least one non-selected word plate

8. The method of claim 7, wherein the fourth voltage is the same as the second voltage.

9. The method of claim 7, wherein the fourth voltage is less than the second voltage.

10. The method of claim 7, wherein applying the third voltage to the selected word plate while applying a fourth voltage less than the third voltage to at least one non-selected word plate comprises applying the third voltage to a selected word plate while applying the fourth voltage to at least one non-selected word plate not immediately adjacent the selected word plate and a fifth voltage less than the fourth voltage to at least one non-selected word plate immediately adjacent the selected word plate.

11. The method of claim 2, wherein selectively driving respective ones of the select gates while applying respective ones of a series of data to the bit line to thereby selectively change the potentials of the column of vertical channels according to the series of data is preceded by loading a plurality of latches with the data and wherein selectively driving respective ones of the select gates while applying respective ones of a series of data to the bit line to thereby selectively change the potentials of the column of vertical channels according to the series of data comprises selectively driving respective ones of the select gates while connecting respective ones of the latches to the bit line to thereby selective change the potentials the column of vertical channels according to the series of data.

12. The method of claim 1, further comprising verifying a programming state of at least one of the memory cells associated with the selected word plate and, responsive to a verification failure, repeating the steps of boosting potentials of the vertical channels, selectively applying respective data to vertical channels via the bit lines to thereby selectively change the potentials of the vertical channels according to the data and applying a program voltage to a selected word plate at a new program voltage level.

13. The method of claim 1, further comprising repeatedly performing the steps of boosting potentials of the vertical channels, selectively applying respective data to vertical channels via the bit lines to thereby selectively change the potentials of the vertical channels according to the data and applying a program voltage to a selected word plate to thereby perform multi-bit programming of the plurality of memory cells.

14. A three-dimensional memory device comprising:

a memory cell array where a plurality of wordline planes are stacked;

a write and read circuit configured to simultaneously program memory cells of at least two pages included in a selected wordline plane; and

a control circuit configured to control a program operation of the write and read circuit.

15. The three-dimensional memory device as set forth in claim 14, wherein the write and read circuit latches program data of at least two pages to be programmed into the memory cells.

16. The three-dimensional memory device as set forth in claim 15, wherein the write and read circuit loads the latched program data in parallel to the memory cells through a plurality of bitlines by the unit of at least one page.

17. The three-dimensional memory device as set forth in claim 14, wherein the control circuit controls channels of the memory cells to be collectively boosted through a plurality of lower select transistors and a common select line corresponding to the memory cells before the program data is loaded to the memory cells.

18. The three-dimensional memory device as set forth in claim 17, wherein the control circuit controls a voltage rising to a predetermined level to be applied to a bitline corresponding to the memory cells during the boosting operation.

19. The three-dimensional memory device as set forth in claim 14, wherein the control circuit controls channels of the memory cells to be collectively boosted through a plurality of upper select transistors and a plurality of bitlines corresponding to the memory cells before the program data is loaded to the memory cells.

20. The three-dimensional memory device as set forth in claim 19, wherein the control circuit controls a voltage rising to a predetermined level to be applied to a common source line corresponding to the memory cells during the boosting operation.

21. The three-dimensional memory device as set forth in claim 14, wherein channels of the memory cells is boosted to a first pass voltage in compliance with the control of the control circuit before program data is loaded to the memory cells.

22. The three-dimensional memory device as set forth in claim 21, wherein the channels of the memory cells is maintained at the first pass voltage or discharged to a ground voltage level according to a value of data to be programmed to the memory cells during a data loading operation to the memory cells.

23. The three-dimensional memory device as set forth in claim 22, wherein states of voltages at the respective channels of the memory cells are determined by the data loading operation and maintained until a program operation is performed.

24. The three-dimensional memory device as set forth in claim 21, wherein when the program data is loaded to the memory cells, the control circuit controls a program operation for the loaded program data to be performed the program operation by applying a program voltage higher than the first pass voltage to the selected wordline plane and applying a second pass voltage equal to or lower than the first pass voltage to unselected wordline planes.

25. The three-dimensional memory device as set forth in claim 24, wherein a difference between the first pass voltage and the second pass voltage is calculated from the amount of charges required to program the memory cells.

26. The three-dimensional memory device as set forth in claim 24, wherein a level of the second pass voltage applied to the respective unselected wordline planes varies with positions of the unselected wordline planes.

27. The three-dimensional memory device as set forth in claim 24, wherein the control circuit controls a local voltage to be applied to at least one wordline plane adjacent to the selected wordline plane among the plurality of unselected wordline planes during the program operation.

28. The three-dimensional memory device as set forth in claim 27, wherein the local voltage is equal to or higher than a ground voltage and lower than the second pass voltage.

29. The three-dimensional memory device as set forth in claim 27, wherein the local voltage is higher than the second pass voltage and lower than the program voltage.

30. The three-dimensional memory device as set forth in claim 27, wherein the control circuit controls the second pass voltage to be applied to at least one unselected wordline plane between the selected wordline plane to which the program voltage is applied and the adjacent wordline plane to which the local voltage is applied during the program operation.

31. A method for programming a three-dimensional memory device, comprising:

performing channel boosting by applying a first pass voltage to a plurality of wordline planes;

loading program data to memory cells of at least two pages disposed at a selected one of the wordline planes; and

simultaneously programming the memory cells to which the program data is loaded.

32. The method as set forth in claim 31, wherein performing channel boosting comprises collectively controlling charge paths to channels of the memory cells through a common select line and a plurality of lower select transistors corresponding to the memory cells.

33. The method as set forth in claim 31, wherein performing channel boosting further comprises boosting a voltage applied to a plurality of bitlines corresponding to the memory cells to a predetermined level.

34. The method as set forth in claim 31, wherein performing channel boosting comprises collectively controlling charges paths to channels of the memory cells through a plurality of bitlines corresponding to the memory cells and a plurality of upper select transistors connected to the respective bitlines.

35. The method as set forth in claim 34, wherein performing channel boosting further comprises boosting a voltage applied to a common source line to a predetermined level.

36. The method as set forth in claim 31, wherein the program data is loaded in parallel through a plurality of bitlines corresponding to the memory cells by the unit of predetermined data.

37. The method as set forth in claim 36, wherein loading program data comprises:

respectively turning on a plurality of upper transistors connected to each bitline connected to the memory cells in sequence;

loading corresponding program data to channels of corresponding memory cells through the respective turned-on upper select transistors;

maintaining or discharging a voltage at the channels of the corresponding memory cells at a level of the first pass voltage or to a level of a ground voltage, depending on values of the respective loaded data; and

respectively turning off the respective turned-on upper select transistors.

38. The method as set forth in claim 31, wherein simultaneously programming the memory cells comprises applying a program voltage higher than the first pass voltage to the selected wordline plane and simultaneously applying a second pass voltage equal to or lower than the first pass voltage to a plurality of unselected wordline planes.

39. The method as set forth in claim 38, wherein charges corresponding to a difference between the first pass voltage and the second pass voltage are separated from the unselected wordline planes and migrate to memory cells of the selected wordline plane.

40. The method as set forth in claim 38, wherein a difference between the first pass voltage and the second pass voltage is calculated from the amount of charges required to program the memory cells of the selected wordline plane.

41. The method as set forth in claim 38, wherein external charge supply to channels of the memory cells is cut off while the first pass voltage and the second pass voltage are applied.

42. The method as set forth in claim 38, wherein simultaneously programming the memory cells further comprises applying a local voltage equal to or higher than a ground voltage and lower than the second pass voltage to at least one wordline plane adjacent to the selected wordline plane.

43. The method as set forth in claim 38, wherein simultaneously programming the memory cells further comprises applying a local voltage higher than the second pass voltage and lower than the program voltage to at least one wordline plane adjacent to the selected wordline plane.

44. The method as set forth in claim 42, wherein simultaneously programming the memory cells further comprises applying the second pass voltage to at least one unselected wordline plane between the selected wordline plane to which the program voltage is applied and the adjacent wordline plane to which the local voltage is applied.

45. The method as set forth in claim 31, wherein the respective memory cells are simultaneously programmed with one or more data bits.

46. A memory system comprising:

a three-dimensional memory device; and

a memory controller configured to control operations of the three-dimensional memory device in response to the request from a host,

wherein the three-dimensional memory device includes a memory cell array where a plurality of wordline planes are stacked, a write and read circuit configured to simultaneously program memory cells of at least two pages included in a selected wordline plane, and a control circuit configured to control a program operation of the write and read circuit.