Magnetic sensor and method of fabricating the same

Patent metadata

Field	Value
Publication number	US-9419206-B2
Application number	US-201313951093-A
Country	US
Kind code	B2
Filing date	Jul 25, 2013
Priority date	Mar 8, 2013
Publication date	Aug 16, 2016
Grant date	Aug 16, 2016

Abstract

Provided are a magnetic sensor and a method of fabricating the same. The magnetic sensor includes: hall elements disposed in a substrate, a protection layer disposed on the substrate, a seed layer disposed on the protection layer, and an integrated magnetic concentrator (IMC) formed on the seed layer, the seed layer and the IMC each having an uneven surface.

First claim

What is claimed is:

1. A magnetic sensor, comprising:
hall elements disposed in a substrate;
a protection layer disposed above the hall elements;
a seed layer disposed above the protection layer and hall elements; and
an integrated magnetic concentrator (IMC) disposed above the seed layer, wherein
the seed layer has an elevated portion that protrudes from an upper surface of the seed layer in a direction substantially normal to an upper surface of the substrate, and
the IMC has an elevated portion that protrudes from an upper surface of the IMC in the direction substantially normal to the upper surface of the substrate.

2. The magnetic sensor of claim 1 , wherein an area of the IMC is equal to or larger than an area of the seed layer.

3. The magnetic sensor of claim 1 , wherein the protection layer comprises a plurality of protrusions formed on a surface thereof.

4. The magnetic sensor of claim 1 , wherein the elevated portion of the seed layer and the elevated portion of the IMC each correspond to a plurality of convex portions in a cross-section of the magnetic sensor, and the upper surface adjacent to the elevated portion of the seed layer and the upper surface adjacent to the elevated portion of the IMC each correspond to one or more concave portions in the cross-section of the magnetic sensor.

5. The magnetic sensor of claim 1 , wherein one of the hall elements has a width which is overlapped by an edge portion of the IMC when viewed in a direction opposite to the direction substantially normal to the upper surface of the substrate.

6. The magnetic sensor of claim 1 , wherein the protection layer comprises a passivation insulating layer and a buffer layer.

7. The magnetic sensor of claim 6 , wherein the protection layer further comprises a corrosion barrier layer.

8. The magnetic sensor of claim 7 , wherein the corrosion barrier layer comprises a silicon oxide layer or a silicon nitride layer.

9. The magnetic sensor of claim 8 , wherein the corrosion barrier layer has a thickness of 5 to 50 nm.

10. The magnetic sensor of claim 6 , wherein the corrosion barrier layer is interposed between the passivation insulating layer and the buffer layer.

11. The magnetic sensor of claim 3 , wherein the protrusions comprises polyimide.

12. The magnetic sensor of claim 1 , wherein the IMC comprises a nickel-iron (NiFe) alloy, and an iron content of the nickel-iron alloy is in a range of 10 to 30 atomic %.

13. The magnetic sensor of claim 1 , wherein the seed layer comprises a titanium tungsten (TiW) layer and a copper (Cu) layer.

14. The magnetic sensor of claim 3 , wherein the plurality of protrusions have a height between 1 μm and 10 μm.

15. The magnetic sensor of claim 1 , wherein the elevated portion of the IMC protrudes upwards from the upper surface of the IMC.

16. The magnetic sensor of claim 1 , further comprising a metal pad disposed on the substrate, wherein the hall elements do not overlap with the metal pad.

17. The magnetic sensor of claim 1 , wherein the seed layer overlaps the hall elements.

18. A magnetic sensor, comprising:
hall elements;
a seed layer disposed above the hall elements; and
an integrated magnetic concentrator (IMC) disposed above the hall elements, the IMC comprising an elevated portion protruding upward from an upper surface of the IMC,
wherein the plurality of hall elements are disposed such that a peripheral edge of the IMC overlaps with a width of the hall elements.

19. The magnetic sensor of claim 18 , wherein the elevated portion of the IMC has a shape of one or more concentric rings.

20. The magnetic sensor of claim 18 , wherein a peripheral edge of the seed layer overlaps the width of the hall elements.

21. The magnetic sensor of claim 18 , wherein the seed layer overlaps the hall elements.

22. A magnetic sensor, comprising:
hall elements;
a protection layer comprising a protrusion that protrudes from an upper surface of the protection layer, the protrusion having a height between 1 μm and 10 μm;
a seed layer disposed above the hall elements; and
an integrated magnetic concentrator (IMC) disposed above the hall elements and the seed layer; the IMC comprising an elevated portion protruding upward from an upper surface of the IMC, the elevated portion overlapping with the protrusion of the protection layer.

23. The magnetic sensor of claim 22 , wherein the seed layer overlaps the hall elements.

Assignees

• Magnachip Semiconductor Ltd

Inventors

• Kim Kwan Soo
• Kim Dong Joon
• Ryu Seung Han
• An Hee Baeg
• Jeong Jong Yeul
• Kim Kyung Soo
• Shin Kang Sup

Classifications

• G01R33/0052

  Manufacturing aspects; Manufacturing of single devices, i.e. of semiconductor magnetic sensor chips (devices based on galvano-magnetic effect or the like H10N50/85) · CPC title

• H01L43/14

  Electricity · mapped topic

• H01L43/065 Primary

  Electricity · mapped topic

• G01R33/0011 Primary

  comprising means, e.g. flux concentrators, flux guides, for guiding or concentrating the magnetic flux, e.g. to the magnetic sensor · CPC title

• G01D5/12 Primary

  using electric or magnetic means (G01D5/06 takes precedence) · CPC title