Magnetic tunnel junction self-alignment in magnetic domain wall shift register memory devices

Abstract

A magnetic domain wall shift register memory device includes a nanowire and a magnetic reference layer island disposed on the nanowire, wherein an interface between the nanowire and the magnetic tunnel junction island is a magnetic tunnel junction aligned with a width of the nanowire.

What is claimed is: 
     
         1 . A magnetic domain wall shift register memory device, comprising:
 a magnetic nanowire; and   a magnetic reference layer island disposed on the nanowire,   wherein an interface between the magnetic nanowire and the magnetic reference layer island is a magnetic tunnel junction (MTJ) aligned with a width of the nanowire.   
     
     
         2 . The device as claimed in  claim 1  wherein the nanowire is a first magnetic material. 
     
     
         3 . The device as claimed in  claim 2  wherein the magnetic reference layer island is a second magnetic material. 
     
     
         4 . The device as claimed in  claim 1  wherein the nanowire is disposed on a substrate. 
     
     
         5 . The device as claimed in  claim 4  wherein the substrate is a first material. 
     
     
         6 . The device as claimed  5  wherein the nanowire is a first magnetic material disposed over the substrate and the magnetic reference layer island is a second magnetic material disposed over the first magnetic material. 
     
     
         7 . The device as claimed in  claim 6  wherein the first material is different from the first magnetic material and the second magnetic material. 
     
     
         8 . The device as claimed in  claim 7  wherein the first magnetic material is different from the second magnetic material. 
     
     
         9 . The device as claimed in  claim 6  wherein the magnetic reference layer island is formed by etching a portion of the second magnetic material. 
     
     
         10 . The device as claimed in  claim 9  wherein the nanowire is formed by etching a portion of the first magnetic material. 
     
     
         11 . A magnetic domain wall shift register memory device, comprising:
 a substrate;   a nanowire disposed on the substrate, and being a first magnetic material; and   a magnetic reference layer island disposed on the nanowire, and being a second magnetic material,   wherein an interface between the nanowire and the magnetic reference layer island is an MTJ aligned with a width of the nanowire.   
     
     
         12 . The device as claimed in  claim 11  wherein the substrate is a material different from the first magnetic material and the second magnetic material. 
     
     
         13 . The device as claimed in  claim 12  wherein the first magnetic material is different from the second magnetic material. 
     
     
         14 . The device as claimed in  claim 13  wherein the magnetic reference layer island is formed by etching a portion of the second magnetic material and retaining the first magnetic material 
     
     
         15 . The device as claimed in  claim 14  wherein the nanowire is formed by etching a portion of the first magnetic material and a portion of the second magnetic material. 
     
     
         16 . A magnetic domain wall shift register memory device, comprising:
 a nanowire patterned on a substrate;   a magnetic tunnel junction (MTJ) island patterned on a portion of the nanowire,   wherein the MTJ island is self-aligned on the portion of the nanowire.   
     
     
         17 . The device as claimed in  claim 16  wherein the substrate is a material different from the first magnetic material and the second magnetic material. 
     
     
         18 . The device as claimed in  claim 17  wherein the first magnetic material is different from the second magnetic material. 
     
     
         19 . The device as claimed in  claim 18  wherein the MTJ island is formed by etching a lithographic strip disposed on the first magnetic material. 
     
     
         20 . The device as claimed in  claim 19  wherein the nanowire is formed by etching a portion of the first magnetic material and the lithographic strip.