MAGNETIC FIELD DETECTOR

• US 20090152657A1
• Filed: 07/10/2008
• Published: 06/18/2009
• Est. Priority Date: 12/14/2007
• Status: Abandoned Application

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Suh, Jeongdae, Chung, Myungae
• Application Number:
  US12/170,744
• Publication Number:
  US 20090152657A1
• Time in Patent Office: Days
• US Class Current: 257/421
• CPC Class Codes: G01R 33/1269 of molecules labeled with magnetic beads magnetic particles for bio assay G01N33/54326

Abstract

Disclosed is a magnetic field detector having various structures that can be used as a high-density magnetic biosensor. An embodiment of the invention provides a magnetic field detector using a thin film for detecting magnetic beads. The magnetic field detector includes: a substrate; a magnetoresistive element that is formed on an upper surface of the substrate in a ring shape using the thin film; electrodes that are formed on the upper surface of the substrate to be connected to the magnetoresistive element; a protective layer that is formed on the magnetoresistive element and the electrodes; and a magnetic bead limiting layer that is formed on an upper surface of the protective layer to cover the entire surface of the magnetoresistive element and portions of the electrodes.

Claims

1. A magnetic field detector comprising:

a magnetoresistive element that is formed in any one of a circular ring shape, an elliptical ring shape, a square ring shape, and a rectangular ring shape.

2. A magnetic field detector using a thin film for detecting magnetic beads, the magnetic field detector comprising:

a substrate;

a magnetoresistive element that is formed on an upper surface of the substrate in a ring shape using the thin film;

electrodes that are formed on the upper surface of the substrate to be connected to the magnetoresistive element;

a protective layer that is formed on the magnetoresistive element and the electrodes; and

a magnetic bead limiting layer that is formed on an upper surface of the protective layer to cover the entire surface of the magnetoresistive element and portions of the electrodes.

3. The magnetic field detector of claim 2,

wherein the thin film is formed of any one of a giant magnetoresistive thin film, an anisotropic magnetoresistive thin film, a spin valve thin film, and a tunnel-type magnetoresistive thin film.

4. The magnetic field detector of claim 2,

wherein the thin film includes a pinned layer and a free layer.

5. The magnetic field detector of claim 2,

wherein the thin film is a laminate of a seed layer, an antiferromegnetic layer, a pinned layer, a gap layer, a free layer, and a protective layer formed in this order.

6. The magnetic field detector of claim 2,

wherein the magnetoresistive element is formed in any one of a circular ring shape, an elliptical ring shape, a square ring shape, and a rectangular ring shape.

7. The magnetic field detector of claim 2,

wherein the electrodes are formed of Ta or Au.

8. The magnetic field detector of claim 2,

wherein the electrodes are formed so as to be horizontally connected to the magnetoresistive element.

9. The magnetic field detector of claim 2,

wherein the electrodes are formed so as to be vertically and horizontally connected to the magnetoresistive element.

10. The magnetic field detector of claim 2,

wherein the protective layer is formed of SiO₂ or Si₃N₄.

11. The magnetic field detector of claim 2,

wherein the protective layer is formed with a thickness of 50 to 300 nm at room temperature.

12. The magnetic field detector of claim 2,

wherein the magnetic bead limiting layer is formed of a photosensitive thin film.

13. The magnetic field detector of claim 2,

wherein the magnetic bead limiting layer is formed with a thickness of 1 to 2 μ

m at room temperature.

14. The magnetic field detector of claim 2,

wherein the outside diameter of the magnetoresistive element is in a range of 100 nm to 30 μ

m.

15. The magnetic field detector of claim 2,

wherein the width of the magnetoresistive element is in a range of 100 nm to 5 μ

m.

16. The magnetic field detector of claim 2,

wherein a plurality of magnetoresistive elements are formed in a one-dimensional array.

17. The magnetic field detector of claim 2,

wherein a plurality of magnetoresistive elements are formed in a two-dimensional array, that is, in a matrix.