Nonvolatile semiconductor memory, fabrication method for the same, semiconductor integrated circuits and systems

• US 6,845,042 B2
• Filed: 02/06/2003
• Issued: 01/18/2005
• Est. Priority Date: 02/05/2003
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Ichige, Masayuki, Shirota, Riichiro, Kuji, Tatsuaki, Hashimoto, Koji, Takeuchi, Yuji, Mori, Seiichi, Sakui, Koji
• Primary Examiner(s): HO, HOAI V
• Application Number:
  US10/359,216
• Publication Number:
  US 20040152262A1
• Time in Patent Office: 712 Days
• Field of Search: 365/185.17, 365/185.12, 365/185.21, 365/185.23
• US Class Current: 365/185.17
• CPC Class Codes: G11C 16/0483 comprising cells having several storage transistors connected in series
• CPC Class Codes: H01L 27/0207 Geometrical layout of the components, e.g. computer aided design; custom LSI, semi-custom LSI, standard cell technique
• CPC Class Codes: H10B 41/10 characterised by the top-view layout
• CPC Class Codes: H10B 41/30 characterised by the memory core region
• CPC Class Codes: H10B 41/35 with a cell select transistor, e.g. NAND
• CPC Class Codes: H10B 69/00 Erasable-and-programmable ROM [EPROM] devices not provided for in groups H10B41/00 - H10B63/00, e.g. ultraviolet erasable-and-programmable ROM [UVEPROM] devices

Abstract

A nonvolatile semiconductor memory which is configured to include a plurality of word lines disposed in a row direction; a plurality of bit lines disposed in a column direction perpendicular to the word lines; memory cell transistors having a charge storage layer, provided in the column direction and an electronic storage condition of the memory cell transistor configured to be controlled by one of the plurality of the word lines connected to the memory cell; a plurality of first select transistors, each including a gate electrode, selecting the memory cell transistors provided in the column direction, arranged in the column direction and adjacent to the memory cell transistors at a first end of the memory cell transistors; and a first select gate line connected to each of the gate electrodes of the first select transistors.

Claims

1. A nonvolatile semiconductor memory comprising:

a plurality of word lines disposed in a row direction;

a plurality of bit lines disposed in a column direction perpendicular to the word lines;

memory cell transistors having a source region, a drain region, a gate electrode and a charge storage layer, provided in the column direction and an electronic storage condition of the memory cell transistor configured to be controlled by one of the plurality of the word lines connected to the memory cell;

a plurality of first select transistors, each including a gate electrode, selecting the memory cell transistors provided in the column direction, arranged in the column direction and adjacent to the memory cell transistors at a first end of the memory cell transistors; and

a first select gate line connected to each of the gate electrodes of the first select transistors, wherein the plurality of the word lines have a wiring line width which is the same as the first select gate line.

2. The nonvolatile semiconductor memory of claim 1, further comprising:

a plurality of second select transistors selecting the memory cell transistors, arranged in the column direction and adjacent to the memory cell transistors at a second end of the memory cell transistors; and

a second select gate line connected to each of the gate electrode of the second select transistors.

3. The nonvolatile semiconductor memory of claim 1, wherein one of a plurality of first select transistors is connected to the bit line.

4. The nonvolatile semiconductor memory of claim 1, wherein the plurality of the word lines have a wiring line width which is the same as the first select gate line, the line width defined by a minimum fabrication dimension.

5. The nonvolatile semiconductor memory of claim 1, wherein the plurality of the first select transistors are driven by different voltages.

6. The nonvolatile semiconductor memory of claim 1, wherein the plurality of the first select transistors are driven by the same voltage.

7. The nonvolatile semiconductor memory of claim 5, wherein the plurality of the first transistors are periodically electrically shorted.

8. The nonvolatile semiconductor memory of claim 1, wherein, the plurality of the memory cell transistors are connected in series.

9. The nonvolatile semiconductor memory of claim 1, wherein, the plurality of the memory cell transistors are disposed in parallel with the bit lines.

10. The nonvolatile semiconductor memory of claim 1, wherein the plurality of the memory cell transistors are disposed in parallel with each other, and the source region of the memory cell transistors is connected to a common source line.

11. The nonvolatile semiconductor memory of claim 1, wherein the memory cell transistors connected in series in the column direction are configured as a memory cell string.

12. The nonvolatile semiconductor memory of claim 11, wherein the memory cell string is configured as a NAND string.

13. The nonvolatile semiconductor memory of claim 11, wherein, the memory cell string is configured as an AND string.

14. The nonvolatile semiconductor memory of claim 11, wherein, the memory cell string is configured as a divided bit line NOR string.

15. The nonvolatile semiconductor memory of claim 1, further comprising:

a sense amplifier configured to act in a page mode for reading and writing information in the memory cell transistors connected to the word lines.

16. The nonvolatile semiconductor memory of claim 1, further comprising:

a sense amplifier configured to act in a byte mode reading and writing information in the memory cell transistor disposed at a cross point of the word lines perpendicular to the bit lines.

17. The nonvolatile semiconductor memory of claim 1, further comprising:

an EEPROM having a ROM region configured to act in a page mode for reading and writing information in the memory cell transistors connected to the word lines.

18. The nonvolatile semiconductor memory of claim 1, further comprising:

an EEPROM having a ROM region configured to act in a byte mode for reading and writing information in the memory cell transistor disposed at a cross point of the word lines perpendicular to the bit lines.

19. The nonvolatile semiconductor memory of claim 1, wherein:

each of the first selecting transistors further comprises,

a first conductive layer;

an inter-gate insulating layer on the first conductive layer; and

a second conductive layer on the inter-gate insulating layer, wherein the first conductive layer is electrically shorted to the second conductive layer through an aperture window opened to the inter-gate insulating layer.

20. The nonvolatile semiconductor memory of claim 1, wherein at least one of the first select transistors further comprises,

a first conductive layer;

an inter-gate insulating layer on the first conductive layer; and

a second conductive layer on the inter-gate insulating layer, wherein, the first conductive layer is electrically shorted to the second conductive layer through an aperture window opened to the inter-gate insulating layer.

21. The nonvolatile semiconductor memory of claim 1, wherein:

an impurity concentration of a channel region of the plurality of the first select transistors is different from an impurity concentration of a channel region of the memory cell transistors.

22. The nonvolatile semiconductor memory device of claim 1, wherein

each of the memory cell transistors and each of the plurality of the first select transistors further comprises,

a first conductive layer;

an inter-gate insulating layer on the first conductive layer; and

a second conductive layer on the inter-gate insulating layer, wherein a thickness of the first conductive layer in the memory cell transistors is the same as a thickness of the first conductive layer in the first select transistors, a thickness of the inter-gate insulating layer in the memory cell transistors is the same as a thickness of the inter-gate insulating layer in the first select transistors, and a thickness of the second conductive layer in the memory cell transistors is the same as a thickness of the second conductive layer in the first select transistors.

23. The nonvolatile semiconductor memory of claim 1, wherein

the memory cell transistors and the plurality of the first select transistors further comprise,

a matrix of a memory cell array which is repeatedly disposed in both the column direction and the row direction perpendicular to the column direction.

24. The nonvolatile semiconductor memory of claim 23, wherein further comprises,

a word line driver selecting the plurality of the word lines of the memory cell array;

and

a page buffer selecting the plurality of the bit lines of the memory cell array, wherein each of the memory cell transistors is connected to one of the bit lines through the plurality of the first select transistors.

68. The nonvolatile semiconductor memory of claim 1, wherein the wiring line width of the plurality of word lines and the wiring line width of the first select gate line is equal to or less than 90 nm.

25. A semiconductor integrated circuit, comprising,

a semiconductor chip;

a semiconductor memory mounted on the semiconductor chip comprising;

a plurality of word lines disposed in a row direction;

a plurality of bit lines disposed in a column direction perpendicular to the word lines;

memory cell transistors having a charge storage layer, disposed in the column direction and an electronic storage condition of the memory cell transistor configured to be controlled by one of the plurality of the word lines connected to the memory cell;

a plurality of first select transistors selecting the memory cell transistors, arranged in the column direction and adjacent to the memory cell transistors at a first end of the memory cell transistors; and

a first select gate line connected to each of the gate electrode of the first select transistors; and

a logic circuit mounted on the semiconductor chip to control the semiconductor memory, wherein the plurality of the word lines have a wiring line width which is the same as the first select gate line.

26. The semiconductor integrated circuit of claim 25, wherein the logic circuits further comprises a CPU.

69. The semiconductor integrated circuit of claim 25, wherein the wiring line width of the plurality of word lines and the wiring line width of the first select gate line is equal to or less than 90 nm.

27. A system for storing information and for accessing a storage medium comprising:

a memory card including a semiconductor memory comprises,

a plurality of word lines disposed in a row direction;

a plurality of bit lines disposed in a column direction perpendicular to the word lines;

memory cell transistors having a charge storage layer, disposed in the column direction and an electronic storage condition of the memory cell transistor configured to be controlled by one of the plurality of the word lines connected to the memory cell;

a plurality of first select transistors selecting the memory cell transistors, arranged in the column direction and adjacent to the memory cell transistors at a first end of the memory cell transistors; and

a first select gate line connected to each of the gate electrode of the first select transistors, wherein the plurality of the word lines have a wiring line width which is the same as the first select gate line.

28. The system of claim 27, wherein the semiconductor memory further comprises:

a plurality of second select transistors selecting the memory cell transistors, arranged in the column direction and adjacent to the memory cell transistors at a second end of the memory cell transistors; and

a second select gate line connected to each of the gate electrode of the second select transistors.

29. The system of claim 27, wherein:

one of a plurality of first select transistors is connected to the bit line.

30. The system of claim 27, wherein:

the plurality of the word lines have a wiring line width which is the same as the first select gate line, the line width is defined by a minimum fabrication dimension.

31. The system of claim 27, wherein:

the plurality of the first select transistors are driven by different voltages.

32. The system of claim 27, wherein:

the plurality of the first select transistors are driven by the same voltage.

33. The system of claim 32, wherein:

the plurality of the first transistors are periodically electrically shorted.

34. The system of claim 27, wherein:

the plurality of the memory cell transistors are connected in series.

35. The system of claim 27, wherein:

the plurality of the memory cell transistors are disposed in parallel with the bit lines.

36. The system of claim 27, wherein:

the plurality of the memory cell transistors are disposed in parallel with each other and the source region of the memory cell transistors is connected to a common source line.

37. The system of claim 27, wherein:

the memory cell transistors connected in series are configured as a memory cell string.

38. The system of claim 37, wherein:

the memory cell string is configured as a NAND string.

39. The system of claim 37, wherein:

the memory cell string is configured as an AND string.

40. The system of claim 37, wherein:

the memory cell string is configured as a divided bit line NOR string.

41. The system of claim 27, further comprising:

a sense amplifier configured to act in a page mode to read and write information in the memory cell transistors connected to the word lines.

42. The system of claim 27, further comprising:

a sense amplifier configured to act in a byte mode to read and write information in the memory cell transistor disposed at a cross point of the word lines perpendicular to the bit lines.

43. The system of claim 27, further comprising:

an EEPROM having a ROM region configured to act in a page mode to read and write information in the memory cell transistors connected to the word lines.

44. The system of claim 27, further comprising:

an EEPROM having a ROM region configured to act in a byte mode to read and write information in the memory cell transistor disposed at a cross point of the word lines perpendicular to the bit lines.

45. The system of claim 27, further comprising:

a memory card holder to receive the memory card.

46. The system of claim 27, further comprising:

a connecting apparatus configured to receive the memory card.

47. The system of claim 46, wherein:

the connecting apparatus is connected to a computer.

48. The system of claim 27, further comprising:

a controller that controls the semiconductor memory.

70. The system of claim 27, wherein the wiring line width of the plurality of word lines and the wiring line width of the first select gate line is equal to or less than 90 nm.

49. A system for storing information and for accessing a storage medium comprising:

an IC card board;

a semiconductor memory disposed on the IC card board, comprising;

a plurality of word lines disposed in a row direction;

a plurality of bit lines disposed in a column direction perpendicular to the word lines;

memory cell transistors having a charge storage layer, disposed in the column direction and an electronic storage condition of the memory cell transistor configured to be controlled by one of the plurality of the word lines connected to the memory cell;

a plurality of first select transistors selecting the memory cell transistors disposed in the column direction, arranged in the column direction and adjacent to the memory cell transistors at a first end of the memory cell transistors disposed in the column direction; and

a first select gate line connected to each of the gate electrodes of the first select transistors, wherein the plurality of the word lines have a wiring line width which is the same as the first select gate line.

50. The system of claim 49, wherein the semiconductor memory further comprises:

a plurality of second select transistors selecting the memory cell transistors, arranged in the column direction and adjacent to the memory cell transistors at a second end of the memory cell transistors; and

a second select gate line connected to each of the gate electrode of the second select transistors.

51. The system of claim 49 wherein:

one of a plurality of first select transistors is connected to the bit line.

52. The system of claim 49 wherein:

the plurality of the word lines have a wiring line width which is the same as the first select gate line, the line width is defined by a minimum fabrication dimension.

53. The system of claim 49 wherein:

the plurality of the first select transistors are driven by different voltages.

54. The system of claim 49 wherein:

the plurality of the first select transistors are driven by the same voltage.

55. The system of claim 54 wherein:

the plurality of the first transistors are periodically electrically shorted.

56. The system of claim 49 wherein:

the plurality of the memory cell transistors are connected in series.

57. The system of claim 49 wherein:

the plurality of the memory cell transistors are disposed parallel with the bit lines.

58. The system of claim 49 wherein:

the plurality of the memory cell transistors are disposed parallel with each other and the source region of the memory cell transistors is connected to a common source line.

59. The system of claim 49, wherein:

the memory cell transistors connected in series are configured as a memory cell string.

60. The system of claim 59, wherein:

the memory cell string is configured as a NAND string.

61. The system of claim 59, wherein:

the memory cell string is configured as an AND string.

62. The system of claim 59, wherein:

the memory cell string is configured as a divided bit line NOR string.

63. The system of claim 49, further comprising:

a sense amplifier configured to act in a page mode to read and write information in the memory cell transistors connected to the word lines.

64. The system of claim 49, further comprising:

a sense amplifier configured to act in a byte mode to read and write information in the memory cell transistor disposed at a cross point of the word lines perpendicular to the bit lines.

65. The system of claim 49, further comprising:

an EEPROM having a ROM region configured to act in a page mode to read and write information in the memory cell transistors connected to the word lines.

66. The system of claim 49, further comprising:

an EEPROM having a ROM region configured to act in a byte mode to read and write information in the memory cell transistor disposed at a cross point of the word lines perpendicular to the bit lines.

67. The system of claim 49 further comprising:

a CPU that controls the semiconductor memory.

71. The system of claim 49, wherein the wiring line width of the plurality of word lines and the wiring line width of the first select gate line is equal to or less than 90 nm.