Dual magnetic tunnel junction device
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- INTERNATIONAL BUSINESS MACHINE CORPORATION
- Filing Date
- 2021-11-17
- Publication Date
- 2026-06-09
Smart Images
Figure 0007872110000001 
Figure 0007872110000002 
Figure 0007872110000003
Abstract
Claims
1. A method for manufacturing a double magnetic tunnel junction device, To form a first magnetic tunnel junction stack, Forming a spin conduction layer on the first magnetic tunnel junction stack, Forming a second magnetic tunnel junction stack on the spin conduction layer, A dielectric spacer layer is formed on the surface of the spin conduction layer and the surface of the second magnetic tunnel junction stack. Includes, The second magnetic tunnel junction stack has a width smaller than the width of the first magnetic tunnel junction stack. The width of the spin conduction layer increases in the thickness direction from the first side surface of the spin conduction layer adjacent to the second magnetic tunnel junction stack to the second side surface of the spin conduction layer adjacent to the first magnetic tunnel junction stack. The upper surface of the spin conduction layer has a curved cross-sectional profile. method.
2. Forming the first magnetic tunnel junction stack is To form the first reference layer, Forming a first tunnel barrier layer on the first reference layer, Forming a first magnetic free layer on the first tunnel barrier layer, Forming a second tunnel barrier layer on the first magnetic free layer and The method according to claim 1, including the method described in claim 1.
3. Forming an etch stop layer on the second magnetic tunnel junction stack, Forming a metal hard mask layer on the aforementioned etch stop layer The method according to claim 2, further comprising:
4. The method according to any one of claims 1 to 3, wherein the increased width of the spin conduction layer is formed by partially etching through the thickness of the spin conduction layer.
5. The method according to claim 4, wherein the formation of the dielectric spacer layer occurs after patterning the second magnetic tunnel junction stack and performing the partial etching through the spin conduction layer, the dielectric spacer layer is formed to cover a portion of the underlying spin conduction layer, and the method further comprises, after forming the dielectric spacer layer, etching the dielectric spacer layer while leaving a portion of the dielectric spacer layer to cover the sidewall of the second magnetic tunnel junction stack and the curved portion of the spin conduction layer to expose a portion of the spin conduction layer.
6. The first magnetic tunnel junction stack is formed on a via dielectric layer, and the method is as follows: The method according to claim 5, further comprising etching through the portion of the spin conduction layer and the first magnetic tunnel junction stack not covered by the dielectric spacer layer, such that the first magnetic tunnel junction stack and the via dielectric layer have a curved cross-sectional profile.
7. The method according to any one of claims 1 to 6, wherein the width of the upper surface of the spin conduction layer is at least substantially the same as the width of the lower surface of the second magnetic tunnel junction stack, and the width of the lower surface of the spin conduction layer is at least substantially the same as the width of the upper surface of the first magnetic tunnel junction stack.
8. The method according to any one of claims 1 to 7, wherein the first magnetic tunnel junction stack is formed by a self-aligned patterning process.
9. The method according to any one of claims 1 to 8, further comprising forming a sealing dielectric layer on the side surface of the dielectric spacer layer and on the side surface of the first magnetic tunnel junction stack.
10. The method according to any one of claims 1 to 9, wherein the sidewall of the second magnetic tunnel junction stack has a cross-sectional profile perpendicular to the spin conduction layer.
11. A double magnetic tunnel junction device, The first magnetic tunnel junction stack, A spin conduction layer formed on the first magnetic tunnel junction stack, A second magnetic tunnel junction stack formed on the spin conduction layer, A dielectric spacer layer formed on the surface of the spin conduction layer and the surface of the second magnetic tunnel junction stack, Equipped with, The second magnetic tunnel junction stack has a width smaller than the width of the first magnetic tunnel junction stack. The width of the spin conduction layer increases in the thickness direction from the first side surface of the spin conduction layer adjacent to the second magnetic tunnel junction stack to the second side surface of the spin conduction layer adjacent to the first magnetic tunnel junction stack. The upper surface of the spin conduction layer has a curved cross-sectional profile. A dual magnetic tunnel junction device.
12. The first magnetic tunnel junction stack is The first reference layer, The first tunnel barrier layer on the first reference layer, The first magnetic free layer on the first tunnel barrier layer, The second tunnel barrier layer on the first magnetic free layer and A double magnetic tunnel junction device according to claim 11, including the above.
13. The etch stop layer on the second magnetic tunnel junction stack and The metal hard mask layer on the aforementioned etch stop layer and The double magnetic tunnel junction device according to claim 12, further comprising:
14. The double magnetic tunnel junction device according to any one of claims 11 to 13, wherein the width of the upper surface of the spin conduction layer is at least substantially the same as the width of the lower surface of the second magnetic tunnel junction stack, the width of the lower surface of the spin conduction layer is at least substantially the same as the width of the upper surface of the first magnetic tunnel junction stack, and the dielectric spacer layer covers the side wall of the second magnetic tunnel junction stack and the curved portion of the spin conduction layer.
15. The double magnetic tunnel junction device according to any one of claims 11 to 14, wherein the first magnetic tunnel junction stack is formed by a self-aligned patterning process.
16. The double magnetic tunnel junction device according to any one of claims 11 to 15, further comprising a sealing dielectric layer formed on the side surface of the dielectric spacer layer and on the side surface of the first magnetic tunnel junction stack.
17. The double magnetic tunnel junction device according to claim 16, further comprising an interlayer dielectric formed on the sealing dielectric layer.
18. The double magnetic tunnel junction device according to claim 17, wherein the first magnetic tunnel junction stack is formed on a via dielectric layer, the first magnetic tunnel junction stack and the via dielectric layer have a curved cross-sectional profile, and the sealing dielectric layer extends below the upper surface of the via dielectric layer.
19. The double magnetic tunnel junction device according to any one of claims 11 to 18, wherein the spin conduction layer is nonmagnetic and comprises at least one material selected from the group consisting of Cu, CuN, Ag, and AgSn.
20. The double magnetic tunnel junction device according to any one of claims 11 to 19, wherein the sidewall of the second magnetic tunnel junction stack has a cross-sectional profile perpendicular to the spin conduction layer.