Granted Patent B2

US 7,683,445 · App. 11/740,066 · Granted Mar 23, 2010

Abstract

Claims (34)

1. A magnetoelectronic device structure comprising:

a programming line;

a magnetoelectronic device magnetically coupled to said programming line;

an enhanced permeability dielectric (EPD) material disposed adjacent to said magnetoelectronic device;

wherein said EPD material comprises multiple superposed composite layers of magnetic material and dielectric material; and

wherein a ratio R=X/Y of an average thickness X of the magnetic material to an average thickness Y of the dielectric material in the composite layers is varied in different layers to provide a predetermined permeability profile in said EPD material.

2. The magnetic device structure of claim 1 , wherein the EPD material comprises at least M layers having thickness ratios R 1 =X 1 /Y 1 and N layers having thickness ratios R 2 =X 2 /Y 2 , wherein R 1 and R 2 are different.

3. The magnetic device structure of claim 1 , wherein the M layers and the N layers are at least partially interleaved.

4. The magnetoelectronic device structure of claim 1 , wherein the dielectric material comprises at least one material selected from the group consisting of alumina, silicon dioxide, silicon nitride, magnesium oxide, hafnium oxide, tantalum oxide, titanium oxide, vanadium oxide, niobium oxide and combinations thereof, and the magnetic material comprise at least one magnetic material selected from the group consisting of nickel, iron, cobalt, alloys of nickel, alloys of iron, alloys of cobalt, combinations thereof and alloys of Co, Fe and B.

5. The magnetoelectronic device structure of claim 1 , wherein said magnetic material comprises superparamagnetic nano-particles with sizes in the range of about 2 nano-meters to about 10 nano-meters.

6. The magnetoelectronic device structure of claim 1 , wherein the multiple superposed composite layers comprises superparamagnetic material having an average thickness X in the range of about 1 to 5 nano-meters and dielectric material having an average thickness Y in the range of about 1 to 10 nm.

7. The magnetoelectronic device structure of claim 1 , wherein said multiple superposed composite layers comprise at least M composite layers of a first thickness ratio R 1 =X 1 /Y 1 and N composite layers of second thickness ratio R 2 =X 2 /Y 2 , wherein R 2 <R 1 .

8. The magnetoelectronic device structure of claim 1 , wherein said multiple superposed composite layers comprise at least M composite layers of a first thickness ratio R 1 =X 1 /Y 1 , N composite layers of second thickness ratio R 2 =X 2 /Y 2 , and P composite layers of a third thickness ratio R 3 =X 3 /Y 3 , wherein R 1 ˜R 3 >R 2 .

9. The magnetoelectronic device structure of claim 8 , wherein the M or P composite layers are closer to the programming line than the N composite layers.

10. The magnetoelectronic device structure of claim 9 , wherein the N, M and P composite layers have total thicknesses T N , T M and T P respectively, and T N <(T M +T P ) and T M and T P are the same or different.

11. A method for making a magnetoelectronic device structure, the method comprising:

in either order;

fabricating a magnetoelectronic device;

depositing a first conducting line; and

forming between the magnetoelectronic device and the first conducting line or laterally around the magnetoelectronic device or both, an enhanced permeability dielectric (EPD) material comprising forming multiple composite layers of dielectric of average thickness Y in which are located nano-particles of a magnetic material of average thickness X, adapted to exhibit superparamagnetic properties, and wherein a ratio R=X/Y is different in at least some of the multiple layers EPD to provide a predetermined permeability profile.

12. The method for making a magnetoelectronic device structure of claim 11 , wherein the step of forming the EPD material is performed:

after the step of depositing a first conducting line and before the step of fabricating a magnetoelectronic device; or

before the step of depositing a first conducting line and after the step of fabricating a magnetoelectronic device.

13. The method for making a magnetoelectronic device structure of claim 11 , wherein the step of forming the EPD material laterally around the magnetoelectronic device is performed:

after the step of depositing a first conducting line and before the step of fabricating a magnetoelectronic device; or

after the step of depositing a first conducting line and after the step of fabricating a magnetoelectronic device.

14. The method for making a magnetoelectronic device structure of claim 11 , wherein the step of forming an EPD material comprises:

forming in any order, M composite layers having a first ratio R 1 =X 1 /Y 1 and N composite layers exhibiting a second ratio R 2 =X 2 /Y 2 different from R 1 , where M≧N.

15. The method for making a magnetoelectronic device structure of claim 14 , wherein the M and N composite layers are at least partially interleaved.

16. A method for fabricating an enhanced permeability dielectric (EPD) material of a predetermined thickness, the method comprising:

forming on a substrate a substantially discontinuous layer of nano-particles exhibiting superparamagnetic properties and of average thickness X;

depositing a layer of dielectric material overlying said discontinuous layer of superparamagnetic nano-particles and of average thickness Y, thereby forming a composite dielectric layer in which said superparamagnetic nano-particles are embedded; and

alternately repeating the forming and depositing steps, to create a stack of said composite layers having the predetermined thickness, wherein X and Y have different values in at least some of the layers, and wherein M layers are formed having a ratio R 1 =X 1 /Y 1 and N layers having a ratio R 2 =X 2 /Y 2 , wherein R 1 ≠R 2 and M>N.

17. The method for fabricating an enhanced permeability dielectric (EPD) material of a predetermined thickness of claim 16 , wherein R 1 and R 2 are in the range of about 0.3 to about 1.0.

Assignments (16)