Method of forming a barrier layer of a tunneling magnetoresistive sensor

• US 6,841,395 B2
• Filed: 11/25/2002
• Issued: 01/11/2005
• Est. Priority Date: 11/25/2002
• Status: Expired due to Fees

• Current Assignee: GlobalFoundries, Inc.
• Original Assignee: International Business Machines Corporation
• Inventors: Mauri, Daniele, Linn, Tsann
• Primary Examiner(s): LEBENTRITT, MICHAEL
• Application Number:
  US10/304,841
• Publication Number:
  US 20040101978A1
• Time in Patent Office: 778 Days
• Field of Search: 438/3, 438/12, 438/286, 438/287, 438/484, 438/737, 257/9
• US Class Current: 438/3
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 25/00 Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: G01R 33/06 using galvano-magnetic devices
• CPC Class Codes: G11B 5/3163 Fabrication methods or processes specially adapted for a particular head structure, e.g. using base layers for electroplating, using functional layers for masking, using energy or particle beams for shaping the structure or modifying the properties of the basic layers
• CPC Class Codes: G11B 5/3903 using magnetic thin film layers or their effects, the films being part of integrated structures
• CPC Class Codes: G11B 5/3909 Arrangements using a magnetic tunnel junction
• CPC Class Codes: G11B 5/40 Protective measures on heads, e.g. against excessive temperature G11B5/31 takes precedence; protection against wear G11B5/255 ; protective structure of the head: see under structures, e.g. G11B5/3106
• CPC Class Codes: H01F 10/3254 the spacer being semiconducting or insulating, e.g. for spin tunnel junction [STJ]
• CPC Class Codes: H01F 10/3268 the exchange coupling being asymmetric, e.g. by use of additional pinning, by using antiferromagnetic or ferromagnetic coupling interface, i.e. so-called spin-valve [SV] structure, e.g. NiFe/Cu/NiFe/FeMn
• CPC Class Codes: H01F 41/18 by cathode sputtering
• CPC Class Codes: H01F 41/303 with exchange coupling adjustment of magnetic film pairs, e.g. interface modifications by reduction, oxidation
• CPC Class Codes: H10N 50/01 Manufacture or treatment
• CPC Class Codes: H10N 50/10 Magnetoresistive devices

Abstract

A fabrication process for a tunneling magnetoresistance (TMR) sensor is disclosed. In particular, a unique method of forming a barrier layer of the TMR sensor is utilized so that the TMR sensor exhibits good magnetic and TMR properties. In one particular example, the barrier layer is formed by depositing a metallic film in an argon gas in a DC magnetron sputtering module, depositing an oxygen-doped metallic film in mixed xenon and oxygen gases in an ion-beam sputtering module, and oxidizing these films in an oxygen gas in an oxygen treatment module. This three-step barrier layer formation process minimizes oxygen penetration into ferromagnetic (FM) sense and pinned layers of the TMR sensor and optimally controls oxygen doping into the barrier layer. As a result, the FM sense and pinned layers exhibit controlled magnetic properties, the barrier layer provides a low junction resistance-area product, and the TMR sensor exhibits a high TMR coefficient.

Claims

1. A method of forming a barrier layer of a tunneling magnetoresistive (TMR) sensor, comprising the acts of:

depositing a metallic film over a ferromagnetic (FM) layer;

depositing an oxygen-doped metallic film over the metallic film; and

performing an oxygen treatment on the oxygen-doped metallic film.

2. The method of claim 1, wherein the barrier layer of the TMR sensor is formed by the acts of depositing the metallic film, depositing the oxygen-doped metallic film, and performing the oxygen treatment.

3. The method of claim 1, wherein the FM layer comprises a first FM layer, the method comprising the further act of:

depositing a second FM layer over the barrier layer.

4. The method of claim 1, wherein the FM layer comprises one of a reference layer and one of a plurality of sense layers of the TMR sensor.

5. The method of claim 1, wherein the act of depositing the metallic film comprises the further act of depositing a metallic film comprising magnesium (Mg).

6. The method of claim 1, wherein the act of depositing the metallic film comprises the further act of depositing the metallic film within a first module, and the act of depositing the oxygen-doped metallic film comprises the further act of depositing the oxygen-doped metallic film within a second module.

7. The method of claim 1, wherein the act of depositing the metallic film comprises the further act of depositing the metallic film within the same module used to deposit the FM layer.

8. The method of claim 1, wherein the act of depositing the metallic film comprises the further act of depositing the metallic film by DC magnetron sputtering.

9. The method of claim 1, wherein the act of depositing the oxygen-doped metallic film comprises the further act of depositing the oxygen-doped metallic film by ion beam reactive sputtering.

10. The method of claim 1, wherein the act of depositing the metallic film comprises the further act of depositing the metallic film with use of a DC magnetron sputtering module, and the act of depositing the oxygen-doped metallic film comprises the further act of depositing the oxygen-doped metallic film with use of an ion beam reactive sputtering module.

11. A method of forming a barrier layer of a tunneling magnetoresistive (TMR) sensor comprising the acts of:

forming a metallic film using a DC magnetron sputtering process;

forming an oxygen-doped metallic film over the metallic film using an ion beam reactive sputtering process; and

performing an oxygen treatment on the oxygen-doped metallic film.

12. The method of claim 11, wherein the metallic film comprises magnesium.

13. The method of claim 11, wherein the act of forming the metallic film comprises forming the metallic film over a ferromagnetic (FM) layer of the TMR sensor.

14. The method of claim 11, further comprising;

wherein the metallic film is formed in a DC magnetron sputtering module; and

wherein the oxygen-doped metallic film is formed in an ion beam sputtering module.