Semiconductor devices with magnetic regions and attracter material and methods of fabrication
View Patent ↗A magnetic cell includes an attracter material proximate to a magnetic region (e.g., a free region). The attracter material is formulated to have a higher chemical affinity for a diffusible species of a magnetic material, from which the magnetic region is formed, compared to a chemical affinity between the diffusible species and at least another species of the magnetic material. Thus, the diffusible species is removed from the magnetic material to the attracter material. The removal accommodates crystallization of the depleted magnetic material. The crystallized, depleted magnetic material enables a high tunnel magnetoresistance, high energy barrier, and high energy barrier ratio. The magnetic region may be formed as a continuous magnetic material, thus enabling a high exchange stiffness, and positioning the magnetic region between two magnetic anisotropy-inducing oxide regions enables a high magnetic anisotropy strength. Methods of fabrication and semiconductor devices are also disclosed.
1. A semiconductor device, comprising:
a structure between a lower electrode and an upper electrode, the structure comprising:
an intermediate oxide region between a free region and a fixed region;
another oxide region adjacent the free region, the other oxide region comprising a nonmagnetic oxide material; and
an attracter material in direct physical contact with the free region and with the nonmagnetic oxide material of the other oxide region, the attracter material chemically bonded to a diffused species diffused from a magnetic material of the free region.
2. The semiconductor device of claim 1 , wherein the free region is above the fixed region and above the lower electrode.
3. The semiconductor device of claim 1 , wherein the free region is configured as a homogeneous region of the magnetic material.
4. The semiconductor device of claim 1 , wherein the attracter material exhibits a crystalline structure.
5. The semiconductor device of claim 1 , wherein the attracter material is integrated in the other oxide region.
6. The semiconductor device of claim 1 , wherein the fixed region is not in physical contact with the attracter material of the structure.
7. The semiconductor device of claim 1 , wherein the free region and the fixed region are above the other oxide region, the attracter material, and the lower electrode.
8. The semiconductor device of claim 1 , wherein the free region and the fixed region are below the other oxide region, the attracter material, and the upper electrode.
9. The semiconductor device of claim 1 , wherein the diffused species consists of boron.
10. The semiconductor device of claim 1 , wherein the attracter material comprises at least one of tantalum (Ta), tungsten (W), hafnium (Hf), and zirconium (Zr).
11. A semiconductor device comprising at least one structure extending vertically from a substrate, the at least one structure comprising:
a nonmagnetic region between a magnetic region and another magnetic region, the magnetic region exhibiting a switchable vertical magnetic orientation, the other magnetic region exhibiting a fixed vertical magnetic orientation;
an attracter region directly adjacent the magnetic region and comprising an attracter material and a species diffused from the magnetic region; and
an oxide material in or adjacent the attracter region.
12. The semiconductor device of claim 11 , wherein the attracter region defines a height of less than about 0.6 nanometers.
13. The semiconductor device of claim 11 , wherein:
the attracter material consists of tantalum (Ta), and
the species diffused from the magnetic region is boron.
14. The semiconductor device of claim 11 , wherein the attracter region further comprises the oxide material.
15. The semiconductor device of claim 11 , wherein the nonmagnetic region is directly between the magnetic region and the other magnetic region.
16. A method of forming a semiconductor device, the method comprising:
forming a precursor structure on a substrate, comprising:
forming a magnetic material above a conductive material supported by the substrate;
forming a nonmagnetic oxide material above the magnetic material;
forming another magnetic material above the nonmagnetic oxide material;
forming another nonmagnetic oxide material adjacent one of the magnetic material and the other magnetic material; and
forming an attracter material in direct physical contact with the one of the magnetic material and the other magnetic material and in direct physical contact with the other nonmagnetic oxide material;
annealing at least a portion of the precursor structure to diffuse a species from the one of the magnetic material and the other magnetic material, the species chemically bonding with the attracter material once the species diffuses; and
patterning the precursor structure to form at least one structure of the semiconductor device.
17. The method of claim 16 :
further comprising forming a foundation material above the substrate; and
wherein forming the attracter material comprises forming the attracter material directly above the foundation material.
18. The method of claim 17 , wherein forming a foundation material comprises forming a CoFeB material.
19. The method of claim 16 , wherein:
forming an attracter material comprises forming the attracter material above the other magnetic material; and
forming another nonmagnetic oxide material comprises forming the other nonmagnetic oxide material above the attracter material.
20. The method of claim 16 , wherein:
forming an attracter material comprises forming the attracter material above the conductive material; and
forming the magnetic material follows forming the attracter material and comprises forming the magnetic material above the attracter material.