Magnetic tunneling junction configuration and a method for making the same

• US 6,897,532 B1
• Filed: 04/15/2002
• Issued: 05/24/2005
• Est. Priority Date: 04/15/2002
• Status: Expired due to Fees

• Current Assignee: Silicon Magnetic Systems Incorporated (Infineon Technologies AG)
• Original Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Inventors: Schwarz, Benjamin C. E., Ounadjela, Kamel
• Primary Examiner(s): Flynn, Nathan J.
• Assistant Examiner(s): Sefer, Ahmed N.
• Application Number:
  US10/122,733
• Time in Patent Office: 1,135 Days
• Field of Search: 257/367, 360/324.2
• US Class Current: 257/367
• CPC Class Codes: B82Y 25/00 Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
• CPC Class Codes: H01F 10/3254 the spacer being semiconducting or insulating, e.g. for spin tunnel junction [STJ]
• CPC Class Codes: H10N 50/01 Manufacture or treatment

Abstract

A method for forming a magnetic tunneling junction (MJT) is provided. In some embodiments, the method may include patterning one or more magnetic layers to form an upper portion of a MTJ. The method may further include patterning one or more additional layers to form a lower portion of the MTJ. In some cases, the lower portion may include a tunneling layer of the MTJ having a width greater than the upper portion. In addition, in some embodiments the method may further include patterning an electrode below the lower portion. In some cases, the electrode may include a lowermost layer with a thickness equal to or less than approximately 100 angstroms. In addition or alternatively, the electrode may have a width greater than the width of the tunneling layer. In yet other embodiments, the method may include forming spacers along the sidewalls of the upper and/or lower portions.

Claims

1. A magnetic tunneling junction, comprising:

a tunneling layer having a width greater than a width of an overlying magnetic layer;

an electrode arranged below the tunneling layer having a width greater than the width of the tunneling layer;

a first set of formed along the sidewalls of the overlying magnetic layer and upon adjacent portions of the tunneling layer, wherein a lateral boundary of the first set of spacers is in alignment with a sidewall of the tunneling layer; and

a second set of spacers formed along the sidewalls of the tunneling layer and upon adjacent portions of the electrode, wherein a lateral boundary of the second set of spacers is spaced apart from a sidewall of the electrode.

2. The magnetic tunneling junction of claim 1, further comprising one or more additional layers interposed between the tunneling layer and the electrode, wherein the one or more additional layers comprise widths substantially similar to the width of the tunneling layer.

3. The magnetic tunneling junction of claim 1, wherein a lateral boundary of the second set of spacers is in alignment with a sidewall of the electrode.

4. The magnetic tunneling junction of claim 1, wherein the width of the tunneling layer is approximately 10 angstroms to approximately 200 angstroms greater than the width of the overlying magnetic layer.

5. The magnetic tunneling junction of claim 1, wherein the overlying magnetic layer comprises a ferromagnetic material.

6. The magnetic tunneling of junction of claim 1, wherein the tunneling layer comprises aluminum oxide.

7. The magnetic tunneling junction of claim 1, wherein a lower-most layer of the electrode comprises a thickness equal to or less than approximately 100 angstroms.

8. A magnetic tunneling junction, comprising:

a tunneling layer having a width greater than a width of an overlying magnetic layer;

an electrode arranged below the tunneling layer and having a width greater than the width of the tunneling layer;

a first set of spacers formed along the sidewalls of the tunneling layer and upon adjacent portions of the electrode, wherein a lateral boundary of the first set of spacers is in a alignment with a sidewall of the electrode; and

a second set of spacers formed along the sidewalls of the overlying magnetic layer and upon adjacent portions of the tunneling layer.

9. The magnetic tunneling junction of claim 8, wherein a lateral boundary of the second set of spacers is in alignment with a sidewall of the tunneling layer.

10. The magnetic tunneling junction of claim 8, wherein a lateral boundary of the second set of spacers is spaced apart from a sidewall of the tunneling layer.

11. The magnetic tunneling junction of claim 8, further comprising one or more additional layers interposed between the tunneling layer and the electrode, wherein the one or more additional layers comprise widths substantially similar to the width of the tunneling layer.

12. The magnetic tunneling junction of claim 8, wherein a lower-most layer of the electrode comprises a thickness equal to or less than approximately 100 angstroms.