Small form factor magnetic shield for magnetorestrictive random access memory (MRAM)

• US 9,276,199 B2
• Filed: 09/26/2014
• Issued: 03/01/2016
• Est. Priority Date: 02/08/2013
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Gu, Shiqun, Zhang, Rongtian, Ramachandran, Vidhya, Kim, Dong Wook
• Primary Examiner(s): Pham, Hoai V
• Application Number:
  US14/499,027
• Publication Number:
  US 20150048465A1
• Time in Patent Office: 522 Days
• Field of Search: 257/294, 257/295, 257/659, 257/660, 257/E21.208, 257/E21.663, 257/E29.164
• US Class Current: 1/1
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/04042 Bonding areas specifically adapted for wire connectors, e.g. wirebond pads
• CPC Class Codes: H01L 2224/131 with a principal constituent of the material being a metal or a metalloid, e.g. boron [B], silicon [Si], germanium [Ge], arsenic [As], antimony [Sb], tellurium [Te] and polonium [Po], and alloys thereof
• CPC Class Codes: H01L 2224/16227 the bump connector connecting to a bond pad of the item
• CPC Class Codes: H01L 23/3121 a substrate forming part of the encapsulation
• CPC Class Codes: H01L 23/552 Protection against radiation, e.g. light or electromagnetic waves
• CPC Class Codes: H01L 23/645 Inductive arrangements H01L23/647, H01L23/66 take precedence
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/014 Solder alloys
• CPC Class Codes: H01L 2924/1435 Random access memory [RAM]
• CPC Class Codes: H01L 2924/157 with a principal constituent of the material being a metal or a metalloid, e.g. boron [B], silicon [Si], germanium [Ge], arsenic [As], antimony [Sb], tellurium [Te] and polonium [Po], and alloys thereof
• CPC Class Codes: H01L 2924/15788 Glasses, e.g. amorphous oxides, nitrides or fluorides
• CPC Class Codes: H01L 2924/3025 Electromagnetic shielding
• CPC Class Codes: H10B 61/00 Magnetic memory devices, e.g. magnetoresistive RAM [MRAM] devices
• CPC Class Codes: H10B 61/22 of the field-effect transistor [FET] type
• CPC Class Codes: H10N 50/01 Manufacture or treatment
• CPC Class Codes: H10N 50/80 Constructional details

Abstract

Some implementations provide a die that includes a magnetoresistive random access memory (MRAM) cell array that includes several MRAM cells. The die also includes a first ferromagnetic layer positioned above the MRAM cell array, a second ferromagnetic layer positioned below the MRAM cell array, and several vias positioned around at least one MRAM cell. The via comprising a ferromagnetic material. In some implementations, the first ferromagnetic layer, the second ferromagnetic layer and the several vias define a magnetic shield for the MRAM cell array. The MRAM cell may include a magnetic tunnel junction (MTJ). In some implementations, the several vias traverse at least a metal layer and a dielectric layer of the die. In some implementations, the vias are through substrate vias. In some implementations, the ferromagnetic material has high permeability and high B saturation.

Claims

1. A die comprising:

a substrate;

at least one dielectric layer;

a component; and

a plurality of vias positioned at least partially around the component, wherein at least one via from the plurality of vias, comprises a ferromagnetic material.

2. The die of claim 1, wherein the component is sensitive to a magnetic field.

3. The die of claim 2, wherein the component is one of at least a transformer, a magnetoresistive random access (MRAM) cell, and/or a component comprising a magnetic material.

4. The die of claim 1, wherein at least one via from the plurality of vias, traverses at least the dielectric layer and/or the substrate of the die.

5. The die of claim 1, wherein the component is a magnetoresistive random access memory (MRAM) cell array comprising a plurality of MRAM cells.

6. The die of claim 5, wherein the plurality of vias is positioned laterally with respect to at least one MRAM cell.

7. The die of claim 1, further comprising a first ferromagnetic layer on a first portion of the die.

8. The die of claim 7, wherein the first ferromagnetic layer is a thin film layer coated on at least a front and/or a back portion of the die.

9. The die of claim 1, wherein the plurality of vias is coupled to a first ferromagnetic layer to define a magnetic shield for the component.

10. The die of claim 1, wherein the component comprises a magnetoresistive random access (MRAM) cell that includes a magnetic tunnel junction (MTJ).

11. The die of claim 1, wherein the ferromagnetic material has high permeability and high B saturation.

12. The die of claim 1, wherein the substrate comprises a material made of one of silicon, glass and/or sapphire.

13. The die of claim 1, wherein the die is incorporated into at least one of a music player, a video player, an entertainment unit, a navigation device, a communications device, a mobile device, a mobile phone, a smartphone, a personal digital assistant, a fixed location terminal, a tablet computer, and/or a laptop computer.

14. A method for fabricating a die that includes a magnetic shield, comprising:

providing a die that includes a substrate, at least one dielectric layer, and a component; and

forming a plurality of vias positioned at least partially around the component, wherein at least one via from the plurality of vias, comprises a ferromagnetic material.

15. The method of claim 14, wherein the component is sensitive to a magnetic field.

16. The method of claim 15, wherein the component is one of at least a transformer, a magnetoresistive random access (MRAM) cell, and/or a component comprising a magnetic material.

17. The method of claim 14, wherein at least one via from the plurality of vias, traverses at least the dielectric layer and/or the substrate of the die.

18. The method of claim 14, wherein the component is a magnetoresistive random access memory (MRAM) cell array comprising a plurality of MRAM cells.

19. The method of claim 18, wherein the plurality of through substrate vias is positioned laterally with respect to at least one MRAM cell.

20. The method of claim 14, wherein the component comprises a magnetoresistive random access (MRAM) cell that includes a magnetic tunnel junction (MTJ).

21. A die comprising:

a substrate;

at least one dielectric layer;

a component; and

a first shielding means traversing the substrate and the at least one dielectric layer, the first shielding means configured to provide shielding of the component from a side magnetic field traversing a side portion of the die.

22. The die of claim 21, wherein the component is sensitive to a magnetic field.

23. The die of claim 22, wherein the component is one of at least a transformer, a magnetoresistive random access (MRAM) cell, and/or a component comprising a magnetic material.

24. The die of claim 21, wherein the component is a magnetoresistive random access memory (MRAM) cell array comprising a plurality of MRAM cells.

25. The die of claim 21, further comprising a second shielding means, different from the first shielding means, configured to provide shielding of the component from a magnetic field traversing one of at least a top portion and/or a bottom portion of the die.

26. The die of claim 21, wherein the component comprises a magnetoresistive random access (MRAM) cell that includes a magnetic tunnel junction (MTJ).

27. The die of claim 21, wherein the die is incorporated into at least one of a music player, a video player, an entertainment unit, a navigation device, a communications device, a mobile phone, a smartphone, a personal digital assistant, a fixed location terminal, a tablet computer, and/or a laptop computer.

28. A die package comprising:

a packaging substrate;

a die coupled to the packaging substrate;

a molding surrounding the die; and

a plurality of vias positioned at least partially around an outer perimeter of the die, the plurality of vias formed in at least the molding, wherein at least one via from the plurality of vias, comprises a ferromagnetic material.

29. The die package of claim 28, wherein the die comprises a component that is sensitive to a magnetic field.

30. The die package of claim 29, wherein the component is one of at least a transformer, a magnetoresistive random access (MRAM) cell, and/or a component comprising a magnetic material.

31. The die package of claim 28, further comprising a first ferromagnetic layer located at least one of below and/or above the die.

32. The die package of claim 31, wherein the first ferromagnetic layer forms an enclosure of the die package.

33. The die package of claim 28, wherein the die comprises a magnetoresistive random access memory (MRAM) cell array comprising a plurality of MRAM cell, the MRAM cell comprising a magnetic tunnel junction (MTJ).

34. The die package of claim 28, wherein the ferromagnetic material has high permeability and high B saturation.

35. The die package of claim 28, wherein the die package is incorporated into at least one of a music player, a video player, an entertainment unit, a navigation device, a communications device, a mobile phone, a smartphone, a personal digital assistant, a fixed location terminal, a tablet computer, and/or a laptop computer.

36. A method for providing a die package that includes a magnetic shield, comprising:

providing a packaging substrate;

providing a die coupled to the packaging substrate;

providing a molding surrounding the die; and

forming a plurality of vias positioned at least partially around an outer perimeter of the die, the plurality of vias formed in at least the molding, wherein at least one via from the plurality of vias, comprises a ferromagnetic material.

37. The method of claim 36, wherein the die comprises a component that is sensitive to a magnetic field.

38. The method of claim 37, wherein the component is one of at least a transformer, a magnetoresistive random access (MRAM) cell, and/or a component comprising a magnetic material.

39. The method of claim 36, further comprising forming a first ferromagnetic layer located at least one of below and/or above the die.

40. The method of claim 36, wherein the die comprises a magnetoresistive random access memory (MRAM) cell array comprising a plurality of MRAM cell, the MRAM cell comprising a magnetic tunnel junction (MTJ).

41. The method of claim 36, wherein the die package is incorporated into at least one of a music player, a video player, an entertainment unit, a navigation device, a communications device, a mobile phone, a smartphone, a personal digital assistant, a fixed location terminal, a tablet computer, and/or a laptop computer.

42. A die package comprising:

a packaging substrate;

a die coupled to the packaging substrate;

a molding surrounding the die; and

a first shielding means traversing the molding surrounding the die, the first shielding means configured to provide shielding of the die from a side magnetic field traversing a side portion of the die package.

43. The die package of claim 42, wherein the die comprises a component that is sensitive to a magnetic field.

44. The die package of claim 43, wherein the component is one of at least a transformer, a magnetoresistive random access (MRAM) cell, and/or a component comprising a magnetic material.

45. The die package of claim 42, wherein the die package further comprises a second shielding means, different from the first shielding means, configured to provide shielding of the die from a magnetic field traversing one of at least a top portion and/or a bottom portion of the die package.

46. The die package of claim 42, wherein the die comprises a magnetoresistive random access memory (MRAM) cell array comprising a plurality of MRAM cell, the MRAM cell comprising a magnetic tunnel junction (MTJ).

47. The die package of claim 42, wherein the die package is incorporated into at least one of a music player, a video player, an entertainment unit, a navigation device, a communications device, a mobile phone, a smartphone, a personal digital assistant, a fixed location terminal, a tablet computer, and/or a laptop computer.