METHOD FOR MANUFACTURING A TUNNEL JUNCTION MAGNETIC SENSOR USING ION BEAM DEPOSITION

• US 20080152834A1
• Filed: 12/22/2006
• Published: 06/26/2008
• Est. Priority Date: 12/22/2006
• Status: Abandoned Application

• Current Assignee: Hitachi Global Storage Technologies Netherlands BV (Western Digital Corporation)
• Original Assignee: Hitachi Global Storage Technologies Incorporated (Western Digital Corporation)
• Inventors: Pinarbasi, Mustafa Michael
• Application Number:
  US11/615,887
• Publication Number:
  US 20080152834A1
• Time in Patent Office: Days
• US Class Current: 427/529
• 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: 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 5/3906 Details related to the use of magnetic thin film layers or to their effects
• CPC Class Codes: G11B 5/3909 Arrangements using a magnetic tunnel junction

Abstract

A method for forming a MgO barrier layer in a tunnel junction magnetoresistive sensor (TMR). The MgO barrier layer is deposited by an ion beam deposition process that results in a MgO barrier layer having exceptional, uniform properties and a well controlled oxygen content. The ion beam deposition of the barrier layer includes placing a wafer into an ion deposition chamber and placing Mg target into the chamber. An ion beam from an ion beam gun is directed at the target thereby dislodging Mg atoms from the target for deposition onto the wafer. Oxygen is introduced into the chamber by one or both of pumping molecular oxygen (O₂) into the chamber and/or introducing oxygen ions into the chamber from a second ion beam gun. The use of ion beam deposition avoids oxygen poisoning of the Mg target, such as would occur using a more conventional plasma vapor deposition technique.

Claims

1. A method for manufacturing a tunnel junction sensor (TMR) comprising:

placing a wafer in an ion beam deposition chamber;

providing a Mg target in the chamber;

directing an ion beam from an ion beam gun at the target such that Mg atoms are dislodged from the target and deposited on the wafer; and

simultaneously with directing the ion beam at the target, introducing oxygen into the chamber.

2. A method as in claim 1 wherein the oxygen introduced into the chamber is molecular oxygen O₂.

3. A method as in claim 1 further comprising, prior to directing an ion beam at the target, providing gas to the ion beam gun.

4. A method as in claim 1 wherein the directing an ion beam at the target further comprises:

feeding a noble gas from the group comprising argon (Ar), krypton (Kr) and xenon (Xe) into the ion beam gun; and

operating the first ion beam gun to ionize the noble gas and accelerate the ionized noble gas toward and onto the target.

5. A method for manufacturing a tunnel junction sensor (TMR), comprising:

providing a wafer;

depositing a layer of antiferromagnetic material onto the wafer;

depositing magnetic pinned layer on the layer of antiferromagnetic material;

depositing a MgO barrier layer on the pinned layer structure; and

depositing a magnetic free layer on the MgO barrier layer, wherein

the depositing a MgO barrier layer further comprises;

placing the wafer in an ion beam deposition chamber;

providing a Mg target in the chamber;

directing an ion beam from an ion beam gun at the target such that Mg atoms are dislodged from the target and deposited on the wafer; and

simultaneously with directing the ion beam at the target, introducing oxygen into the chamber.

6. A method as in claim 5 wherein the oxygen introduced into the chamber is molecular oxygen O₂.

7. A method as in claim 5 further comprising, prior to directing an ion beam at the target, providing gas to the ion gun.

8. A method as in claim 5 wherein the directing an ion beam at the target further comprises:

feeding a noble gas from the group comprising argon (Ar), krypton (Kr) and xenon (Xe) into the ion beam gun; and

operating the first ion beam gun to ionize the noble gas and accelerate the ionized noble gas toward and onto the target.

9. A method for manufacturing a tunnel junction sensor (TMR) comprising:

placing a wafer in an ion beam deposition chamber;

providing a Mg target in the chamber;

directing an ion beam from a first ion beam gun at the target such that Mg atoms are dislodged from the target and deposited on the wafer; and

simultaneously with directing the ion beam at the target, introducing ionized oxygen into the chamber.

10. A method as in claim 9 wherein the ionized oxygen is introduced into the chamber without acceleration.

11. A method as in claim 9 wherein the ionized oxygen is introduced into the chamber from a second ion beam gun that does not accelerate the oxygen ions.

12. A method as in claim 9 wherein the oxygen is introduced into the chamber from a second ion beam gun that accelerates the oxygen ions toward the wafer.

13. A method as in claim 9 wherein the oxygen is introduced into the chamber by a second ion beam gun that is directed toward the wafer.

14. A method for manufacturing a tunnel junction sensor, comprising:

providing a wafer;

depositing a layer of antiferromagnetic material onto the wafer;

depositing a magnetic pinned layer structure onto the layer of antiferromagnetic material;

depositing a MgO barrier layer onto the pinned layer structure; and

depositing a magnetic free layer onto the MgO barrier layer;

wherein

the depositing a MgO barrier layer further comprises;

placing a wafer in an ion beam deposition chamber;

providing a Mg target in the chamber;

directing an ion beam from a first ion beam gun at the target such that Mg atoms are dislodged from the target and deposited on the wafer; and

simultaneously with directing the ion beam at the target, introducing ionized oxygen into the chamber.

15. A method as in claim 14 wherein the ionized oxygen is introduced into the chamber by an ion beam gun without acceleration.

16. A method as in claim 14 wherein the ionized oxygen is introduced into the chamber by an ion beam gun that accelerates the oxygen ions toward the wafer.

17. A method for manufacturing a tunnel junction sensor (TMR) comprising:

placing a wafer in an ion beam deposition chamber;

providing a Mg target in the chamber;

directing an ion beam from a first ion beam gun at the target such that Mg atoms are dislodged from the target and deposited on the wafer; and

simultaneously with directing the ion beam at the target, introducing ionized oxygen and molecular oxygen (O₂) into the chamber.

19. A method as in claim 18 wherein the ionized oxygen is introduced into the chamber from a second ion beam gun, and the molecular oxygen is introduced into the chamber from a gas inlet.

20. A method as in claim 18 wherein the ionized oxygen is introduced into the chamber without acceleration and the molecular oxygen is introduced into the chamber from a gas inlet.

21. A method as in claim 18 wherein the ionized oxygen is introduced into the chamber from an ion beam gun that accelerates the ions toward the wafer, and wherein the molecular oxygen is introduced into the chamber from a gas inlet.