Logic process DRAM

• US 6,947,324 B1
• Filed: 12/12/2003
• Issued: 09/20/2005
• Est. Priority Date: 06/28/2000
• Status: Expired due to Term

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell International Limited (Marvell Technology Group Limited)
• Inventors: Lee, Winston, Sutardja, Sehat, Lee, Peter
• Primary Examiner(s): Nguyen, Viet Q.
• Application Number:
  US10/734,060
• Time in Patent Office: 648 Days
• Field of Search: 365/185.05, 365/149, 257/288, 257/300, 257/68, 257/71, 257/908
• US Class Current: 365/185.05
• CPC Class Codes: G11C 11/4097 Bit-line organisation, e.g. bit-line layout, folded bit lines
• CPC Class Codes: G11C 7/18 Bit line organisation; Bit line lay-out
• 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 12/482 Bit lines
• CPC Class Codes: Y10S 257/908 Dram configuration with transistors and capacitors of pairs of cells along a straight line between adjacent bit lines

Abstract

A semiconductor integrated circuit device including a dynamic random access memory (DRAM) unit having improved signal-to-noise ratio, reduced bit line capacitance, and reduced area is provided. The DRAM unit includes a plurality of bit line pairs, each bit line pair including a first metal conductor and a second metal conductor. Each bit line pair includes a reference bit line and a sense bit line. Each bit line pair may be configured such that the reference bit line and the sense bit line are longitudinally oriented with respect to each other. Alternatively, each bit line pair is configured such that the first metal conductor and the second metal conductor are symmetrically twisted about each other in at least one location. The lateral spacing between a cell plate and a transistor gate is minimized, resulting in reduced overall area.

Claims

1. A semiconductor integrated circuit device, wherein the semiconductor integrated circuit device includes a substrate and a plurality of memory cells, and wherein each of the plurality of memory cell comprises:

a transistor,

wherein the transistor includes a gate;

a gate oxide,

wherein the gate oxide is arranged between the gate and the substrate;

a cell plate,

wherein the cell plate is separated from the gate by a predetermined distance, and

wherein a portion of the cell plate overlaps a portion of the gate; and

a dielectric material arranged between the cell plate, the gate and the substrate,

wherein the dielectric material comprises a high dielectric constant.

2. The semiconductor integrated circuit device of claim 1, wherein the gate comprises polysilicon.

3. The semiconductor integrated circuit device of claim 1, wherein the cell plate comprises one of polysilicon and a metal conductor.

4. The semiconductor integrated circuit device of claim 1, wherein the dielectric material comprises one of tantalum oxide, aluminum oxide, silicon nitride and oxinitride.

5. The semiconductor integrated circuit device of claim 1, wherein the cell plate and the gate are positioned in different planes.

6. The semiconductor integrated circuit device of claim 1, wherein the gate is substantially coplanar with another portion of the cell plate.

7. The semiconductor integrated circuit device of claim 1, wherein the semiconductor integrated circuit device is manufactured using a logic process.

8. The semiconductor integrated circuit device of claim 1, wherein the semiconductor integrated circuit device is manufactured using a DRAM process.

9. An apparatus for reducing area in a dynamic random access memory (DRAM) device, wherein the DRAM device includes a substrate means and a plurality of means for storing data, and wherein each of the plurality of means for storing data comprises:

a transistor means for switching,

wherein the transistor means includes a gate means;

a gate insulating means for insulating the gate means from the substrate means;

a cell plate means for providing an electric field,

wherein the cell plate means is separated from the gate means by a predetermined distance, and

wherein a portion of the cell plate means overlaps a portion of the gate means; and

a dielectric means for separating the cell plate means from the gate means and the substrate means,

wherein the dielectric means comprises a high dielectric constant.

10. The apparatus of claim 9, wherein the gate means comprises polysilicon.

11. The apparatus of claim 9, wherein the cell plate means comprises one of polysilicon and a metal conductor.

12. The apparatus of claim 9, wherein the dielectric means comprises one of tantalum oxide, aluminum oxide, silicon nitride and oxinitride.

13. The apparatus of claim 9, wherein the cell plate means and the gate means are positioned in different planes.

14. The apparatus of claim 9, wherein the gate means is substantially coplanar with another portion of the cell plate means.

15. The apparatus of claim 9, wherein the DRAM device is manufactured using a logic process.

16. The apparatus of claim 9, wherein the DRAM device is manufactured using a DRAM process.

17. A method of reducing area in a dynamic random access memory (DRAM) device, wherein the DRAM device includes a substrate and a plurality of memory cells, wherein each of the plurality of memory cells includes a transistor, wherein the transistor includes a gate and a cell plate, and wherein the method comprises the steps of:

arranging a gate oxide between the gate and the substrate;

separating the cell plate from the gate by a predetermined distance,

wherein a portion of the cell plate overlaps a portion of the gate; and

arranging a dielectric material between the cell plate, the gate and the substrate,

wherein the dielectric material comprises a high dielectric constant.

18. The method of claim 17, wherein the gate comprises polysilicon.

19. The method of claim 17, wherein the cell plate comprises one of polysilicon and a metal conductor.

20. The method of claim 17, wherein the dielectric material comprises one of tantalum oxide, aluminum oxide, silicon nitride and oxinitride.

21. The method of claim 17, further comprising the step of:

positioning the cell plate and the gate in different planes.

22. The apparatus of claim 17, further comprising the step of:

positioning the gate substantially coplanar with another portion of the cell plate.

23. The method of claim 17, wherein the DRAM device is manufactured using a logic process.

24. The method of claim 17, wherein the DRAM device is manufactured using a DRAM process.

25. A semiconductor integrated circuit device, wherein the semiconductor integrated circuit device includes a substrate and a plurality of memory cells, and wherein each of the plurality of memory cell comprises:

a transistor,

wherein the transistor includes a gate;

a gate oxide,

wherein the gate oxide is arranged between the gate and the substrate;

a cell plate,

wherein the cell plate is laterally separated from the gate by a predetermined distance; and

a dielectric material arranged between the cell plate and the gate and between the cell plate and the substrate,

wherein the dielectric material comprises a high dielectric constant.

26. The semiconductor integrated circuit device of claim 25, wherein the gate comprises polysilicon.

27. The semiconductor integrated circuit device of claim 25, wherein the cell plate comprises one of polysilicon and a metal conductor.

28. The semiconductor integrated circuit device of claim 25, wherein the dielectric material comprises one of tantalum oxide, aluminum oxide, silicon nitride and oxinitride.

29. The semiconductor integrated circuit device of claim 25, wherein the semiconductor integrated circuit device is manufactured using a logic process.

30. The semiconductor integrated circuit device of claim 25, wherein the semiconductor integrated circuit device is manufactured using a DRAM process.

31. An apparatus for reducing area in a dynamic random access memory (DRAM) device, wherein the DRAM device includes a substrate means and a plurality of means for storing data, and wherein each of the plurality of means for storing data comprises:

a transistor means for switching,

wherein the transistor means includes a gate means;

a gate insulating means for insulating the gate means from the substrate means;

a cell plate means for providing an electric field,

wherein the cell plate means is laterally separated from the gate means by a predetermined distance; and

a dielectric means for separating the cell plate means from the gate means and the cell plate means from the substrate means,

wherein the dielectric means comprises a high dielectric constant.

32. The apparatus of claim 31, wherein the gate means comprises polysilicon.

33. The apparatus of claim 31, wherein the cell plate means comprises one of polysilicon and a metal conductor.

34. The apparatus of claim 31, wherein the dielectric means comprises one of tantalum oxide, aluminum oxide, silicon nitride and oxinitride.

35. The apparatus of claim 31, wherein the DRAM device is manufactured using a logic process.

36. The apparatus of claim 31, wherein the DRAM device is manufactured using a DRAM process.

37. A method of reducing area in a dynamic random access memory (DRAM) device, wherein the DRAM device includes a substrate and a plurality of memory cells, wherein each of the plurality of memory cells includes a transistor, wherein the transistor includes a gate and a cell plate, and wherein the method comprises the steps of:

arranging a gate oxide between the gate and the substrate;

laterally separating the cell plate from the gate by a predetermined distance; and

arranging a dielectric material between the cell plate and the gate and between the cell plate and the substrate,

wherein the dielectric material comprises a high dielectric constant.

38. The method of claim 37, wherein the gate comprises polysilicon.

39. The method of claim 37, wherein the cell plate comprises one of polysilicon and a metal conductor.

40. The method of claim 37, wherein the dielectric material comprises one of tantalum oxide, aluminum oxide, silicon nitride and oxinitride.

41. The method of claim 37, wherein the DRAM device is manufactured using a logic process.

42. The method of claim 37, wherein the DRAM device is manufactured using a DRAM process.