Method and apparatus for depositing a magnetoresistive multilayer film

• US 7,914,654 B2
• Filed: 03/20/2007
• Issued: 03/29/2011
• Est. Priority Date: 10/16/2003
• Status: Active Grant

• Current Assignee: Anelva Corporation (Canon Inc.)
• Original Assignee: Anelva Corporation (Canon Inc.)
• Inventors: Tsunekawa, Koji, Djayaprawira, David Djulianto, Nagai, Motonobu
• Primary Examiner(s): MCDONALD, RODNEY GLENN
• Application Number:
  US11/688,739
• Publication Number:
  US 20070169699A1
• Time in Patent Office: 1,470 Days
• Field of Search: 204/192.2, 204/298.07, 204/298.03, 204/298.18, 204/298.28
• US Class Current: 204/298.03
• 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 33/093 using multilayer structures, e.g. giant magnetoresistance sensors thin magnetic films H01F10/00
• CPC Class Codes: G11B 5/39 using magneto-resistive devices or effects
• CPC Class Codes: G11C 11/16 using elements in which the storage effect is based on magnetic spin effect
• CPC Class Codes: H01F 10/30 characterised by the composition of the intermediate layers , e.g. seed, buffer, template, diffusion preventing, cap layers H01F10/06 and H01F10/32 take precedence
• 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 41/302 for applying spin-exchange-coupled multilayers, e.g. nanostructured superlattices spin-exchange-coupled multilayers H01F10/32
• CPC Class Codes: H10N 50/01 Manufacture or treatment
• CPC Class Codes: Y10T 29/49025 Making disc drive
• CPC Class Codes: Y10T 29/49032 Fabricating head structure or component thereof
• CPC Class Codes: Y10T 29/49034 Treating to affect magnetic properties
• CPC Class Codes: Y10T 29/49043 Depositing magnetic layer or coating
• CPC Class Codes: Y10T 29/49044 Plural magnetic deposition layers

Abstract

This application discloses a method and apparatus for manufacturing a magnetoresistive multilayer film having a structure where an antiferromagnetic layer, a pinned-magnetization layer, a nonmagnetic spacer layer and a free-magnetization layer are laminated on a substrate in this order. A film for the antiferromagnetic layer is deposited by sputtering as oxygen gas is added to a gas for the sputtering. A film for an extra layer interposed between the substrate and the antiferromagnetic layer is deposited by sputtering as oxygen gas is added to a gas for the sputtering. The film for the antiferromagnetic layer is deposited by sputtering as a gas mixture of argon and another gas of larger atomic number than argon is used.

Claims

1. A system for manufacturing a tunnel-type magnetoresistive multilayer film where an antiferromagnetic layer, a pinned-magnetization layer, a nonmagnetic insulating spacer layer and a free-magnetization layer are laminated on a substrate, comprising:

a vacuum chamber having a pumping line connected thereto;

a substrate holder provided in the vacuum chamber to hold the substrate;

a cathode provided in the vacuum chamber to ignite a sputter discharge;

a gas introduction line capable of introducing argon and a gas of larger atomic number than argon into the vacuum chamber;

valves provided on the gas introduction line so that the gas of larger atomic number than argon is introduced into the vacuum chamber when the antiferromagnetic layer is deposited on the substrate by the sputter discharge, and so that argon is introduced into the vacuum chamber when the pinned-magnetization layer, the nonmagnetic insulating spacer layer and the free-magnetization layer are deposited on the substrate by the sputter discharge; and

a controller to control a flow rate of the gas of larger atomic number than argon in a range from 10 percent to 50 percent when the film for the antiferromagnetic layer is deposited on the substrate by the sputter discharge, wherein

the gas of larger atomic number than argon is krypton or xenon, and

the pinned-magnetization layer is the layer where direction of magnetization is pinned by coupling with the antiferromagnetic layer, and the free-magnetization layer is the layer where direction of magnetization is free.

3. A system for manufacturing a tunnel-type magnetoresistive multilayer film as claimed in claim 1, wherein

the gas introduction line is capable of introducing a mixture of argon and the gas of larger atomic number than argon into the vacuum chamber, and

the valves are so that the gas mixture is introduced into the vacuum chamber when the film for the antiferromagnetic layer is deposited.

5. A system for manufacturing a tunnel-type magnetoresistive multilayer film as claimed in claim 1, wherein

the gas of larger atomic number than argon is krypton,

the gas introduction line is capable of introducing a mixture of argon and the gas of larger atomic number than argon into the vacuum chamber, and capable of introducing oxygen into the vacuum chamber, and

the valves are provided so that the gas mixture is introduced into the vacuum chamber as oxygen is added to the mixture when the film for the antiferromagnetic layer is deposited.

7. A system for manufacturing a tunnel-type magnetoresistive multilayer film as claimed in claim 1, wherein

the cathode has a target for the sputter discharge;

and

the target is made of platinum and manganese.

8. A system for manufacturing a tunnel-type magnetoresistive multilayer film as claimed in claim 3, wherein

the cathode has a target for the sputter discharge;

and

the target is made of platinum and manganese.

2. A system for manufacturing a tunnel-type magnetoresistive multilayer film where an antiferromagnetic layer, a pinned-magnetization layer, a nonmagnetic insulating spacer layer and a free-magnetization layer are laminated on a substrate, comprising:

a vacuum chamber having a pumping line connected thereto;

a substrate holder provided in the vacuum chamber to hold the substrate;

cathodes provided in the vacuum chamber to ignite sputter discharges;

targets provided in the cathodes for depositing films for the antiferromagnetic layer, the pinned-magnetization layer, the nonmagnetic insulating spacer layer and the free-magnetization layer respectively;

a rotation mechanism to place the substrate in front of one of the targets;

a gas introduction line capable of introducing argon and a gas of larger atomic number than argon into the vacuum chamber;

valves provided on the gas introduction line so that the gas of larger atomic number than argon is introduced into the vacuum chamber when the film for the antiferromagnetic layer is deposited on the substrate by the sputter discharge, and so that argon is introduced into the vacuum chamber when the pinned-magnetization layer, the nonmagnetic insulating spacer layer and the free-magnetization layer are deposited on the substrate by the sputter discharge; and

a controller to control a flow rate of the gas of larger atomic number than argon in a range from 10 percent to 50 percent when the antiferromagnetic layer is deposited on the substrate by the sputter discharge, wherein

the gas of larger atomic number than argon is krypton or xenon, and

the pinned-magnetization layer is the layer where direction of magnetization is pinned by coupling with the antiferromagnetic layer, and the free-magnetization layer is the layer where direction of magnetization is free.

4. A system for manufacturing a tunnel-type magnetoresistive multilayer film as claimed in claim 2, wherein

the gas introduction line is capable of introducing a mixture of argon and the gas of larger atomic number than argon into the vacuum chamber, and

the valves are so that the gas mixture is introduced into the vacuum chamber when the film for the antiferromagnetic layer is deposited.

6. A system for manufacturing a tunnel-type magnetoresistive multilayer film as claimed in claim 2, wherein

the gas of larger atomic number than argon is krypton,

the gas introduction line is capable of introducing a mixture of argon and the gas of larger atomic number than argon into the vacuum chamber, and capable of introducing oxygen into the vacuum chamber, and

the valves are provided so that the gas mixture is introduced into the vacuum chamber as oxygen is added to the mixture when the film for the antiferromagnetic layer is deposited.

9. A system for manufacturing a tunnel-type magnetoresistive multilayer film as claimed in claim 2, wherein

a first one of the targets for depositing a first one of the films for the antiferromagnetic layer is made of PtMn or IrMn;

a second one of the targets for depositing a second one of the films for the nonmagnetic insulating spacer layer is made of alumina; and

a third one of the targets for depositing a third one of the films for the free-magnetization layer is made of NiFe.

10. A system for manufacturing a tunnel-type magnetoresistive multilayer film as claimed in claim 4, wherein

a first one of the targets for depositing a first one of the films for the antiferromagnetic layer is made of PtMn or IrMn;

a second one of the targets for depositing a second one of the films for the nonmagnetic insulating spacer layer is made of alumina; and

a third one of the targets for depositing a third one of the films for the free-magnetization layer is made of NiFe.