Magnetic sensor with tilted magnetoresistive structures

• US 20060171081A1
• Filed: 01/20/2006
• Published: 08/03/2006
• Est. Priority Date: 01/21/2005
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Crolly, Guenther, Brcuer, Marcus, Paul, Johannes, Haag, Michael, Schaefer, Rolf, Muehge, Thorsten, Jung, Manfred, Welzel, Alexandra, Sauerwein, Joerg
• Granted Patent: US 7,492,554 B2
• Time in Patent Office: Days
• US Class Current: 360/313
• CPC Class Codes: G01R 33/0206 Three-component magnetometers
• CPC Class Codes: G11B 2005/3996 large or giant magnetoresistive effects [GMR], e.g. as generated in spin-valve [SV] devices
• CPC Class Codes: G11B 5/3909 Arrangements using a magnetic tunnel junction
• CPC Class Codes: G11B 5/3951 the active elements being arranged on several parallel planes

Abstract

A magnetic field sensor device comprising a substrate having at least a first tilted planar section having a surface normal at a first angle with respect to a surface normal of the substrate, and at least a first magnetoresistive layered structure positioned at the at least first tilted section. Methods for manufacturing magnetic field sensor devices are also presented.

Claims

1. A magnetic field sensor device comprising:

a substrate having at least a first tilted planar section having a surface normal at a first angle with respect to a surface normal of the substrate, and

at least a first magnetoresistive layered structure positioned at the at least first tilted section.

2. The magnetic field sensor device according to claim 1, further comprising:

at least a second tilted planar section having a surface normal at a second angle with respect to the surface normal of the substrate and with respect to the first angle, and

at least a second magnetoresistive layered structure positioned at the at least second tilted section.

3. The magnetic field sensor device according to claim 2,

wherein the at least first tilted planar section is tilted with respect to a first tilt axis and the at least second tilted planar section is tilted with respect to a second tilt axis, the first and second tilt axes being substantially parallel.

4. The magnetic field sensor device according to claim 3, wherein the at least first and second tilted planar sections are tilted in opposite directions and wherein the first and second angles have a substantially equal absolute value.

5. The magnetic field sensor device according to claim 1, wherein the at least first magnetoresistive layered structure is sensitive to a component of a magnetic field pointing in a direction substantially parallel or anti-parallel to the surface normal of the substrate.

6. The magnetic field sensor device according to claim 1, further comprising at least one other tilted planar section being tilted with respect to another tilt axis lying in the plane of the substrate and being substantially perpendicular to the tilt axis of the first tilted planar section, the at least one other tilted planar section further comprising a magnetoresistive layered structure.

7. The magnetic field sensor device according to claim 1, wherein the at least first magnetoresistive layered structure is electrically connected to at least one other magnetoresistive layered structure having a surface normal being substantially parallel to the surface normal of the at least first magnetoresistive layered structure.

8. The magnetic field sensor device according to claim 2, wherein the at least first magnetoresistive layered structure is electrically connected with the at least second magnetoresistive layered structure.

9. The magnetic field sensor device according to claim 1, wherein the at least first magnetoresistive layered structure is electrically interconnected with at least one other magnetoresistive layered structure, thereby forming a bridge circuit.

10. The magnetic field sensor device according to claim 1, wherein the at least first magnetoresistive layered structure is electrically connected to at least one contact electrode.

11. The magnetic field sensor device according to claim 1, wherein the first angle is determined by a crystallographic axis of the substrate.

12. The magnetic field sensor device according to claim 11, wherein the first angle is determined by means of at least one of a [111], [110] and [100] crystallographic axis of the substrate.

13. The magnetic field sensor device according to claim 1, wherein the at least first tilted planar section is formed at least in part by an anisotropic wet etching process.

14. The magnetic field sensor device according to claim 1, wherein the at least first magnetoresistive layered structure includes an element selected from a group consisting of a Giant Magnetoresistive Spinvalve element, a Giant Magnetoresistive Multilayer element and a Tunnel Magnetoresistive element.

15. The magnetic field sensor device according to claim 2, further comprising at least a third tilted planar section being tilted with respect to a third tilt axis lying in the plane of the substrate and being substantially perpendicular to the tilt axis of the first tilted planar section, at least a third magnetoresistive layered structure positioned at the at least third tilted planar section.

16. The magnetic field sensor device according to claim 2, wherein the first and second angles are different.

17. A magnetic field sensor device comprising:

a substrate having a plurality of tilted planar sections, each of the tilted planar sections having a surface normal angled with respect to a surface normal of the substrate, and

a magnetoresistive layered structure positioned at each of the tilted sections,

wherein the tilted planar sections are oriented such that a direction of an applied magnetic field in at least one of an x-, y- and z-direction relative to the substrate is detectable based on field-induced resistance changes of the magnetoresistive layered structures.

18. A method of manufacturing a magnetic field sensor device, the method comprising:

applying a mask on a substrate,

performing a wet etching procedure on the substrate for generating at least a first groove having tilted side walls, and

depositing at least one layer of magnetoresistive material onto a section of the surface of at least a first tilted side wall of the groove.

19. The method according to claim 18, wherein depositing the at least one layer of magnetoresistive material further comprises:

depositing the at least one layer of magnetoresistive material onto the section of the surface of the at least first tilted side wall of the groove,

depositing a layer of photoresist on top of the at least one layer of magnetoresistive material,

exposing the layer of photoresist with a spatial pattern of electromagnetic radiation,

developing the spatial pattern and removing the photoresist at first sections,

performing an ion mill procedure for removing the magnetoresistive material at the first sections, and

removing the photoresist at second sections.

20. The method according to claim 18, further comprising determining the thickness of the at least one layer of magnetoresistive material during deposition of the magnetoresistive material by determining a thickness of a reference layer having a surface being substantially parallel to the surface of the substrate, thickness of the reference layer and thickness of the at least one layer of magnetoresistive material being correlated, wherein the correlation being determinable by means of a calibration procedure.