Non volatile memory including stabilizing structures

Abstract

An apparatus that includes a magnetic structure including a reference layer; and a free layer; an exchange coupling spacer layer; and a stabilizing layer, wherein the exchange coupling spacer layer is between the magnetic structure and the stabilizing layer and exchange couples the free layer of the magnetic structure to the stabilizing layer.

1 . A non volatile memory cell comprising:
 a magnetic tunnel junction (MTJ) stack comprising:
 a reference layer; 
 a tunnel barrier; and 
 a recording layer having a thermal stability, 
 wherein the tunnel barrier is between the reference layer and the recording layer; 
   an exchange coupling spacer layer; and   a stabilizing structure,   wherein the exchange coupling spacer layer is between the STRAM structure and the stabilizing structure and exchange couples the recording layer of the STRAM structure to the stabilizing structure, thereby increasing the thermal stability of the recording layer relative to a recording layer not exchange coupled to a stabilizing structure.   
     
     
         2 . The non volatile memory cell according to  claim 1 , wherein the MTJ stack has an aspect ratio of about 1. 
     
     
         3 . The non volatile memory cell according to  claim 1 , wherein the total thermal barrier factor (KuV/kT) of the recording layer is about 40 or more. 
     
     
         4 . The non volatile memory cell according to  claim 3 , wherein the recording layer is more stable at room temperature than a recording layer not exchange coupled to a stabilizing structure. 
     
     
         5 . The non volatile memory cell according to  claim 1 , wherein the exchange coupling between the recording layer of the STRAM cell and the stabilizing structure has a strength from about 50 to about 500 Oe. 
     
     
         6 . The non volatile memory cell according to  claim 1 , wherein the exchange coupling spacer layer comprises copper, tantalum, ruthenium, magnesium oxide, or combinations thereof 
     
     
         7 . The non volatile memory cell according to  claim 1 , wherein the stabilizing structure comprises a synthetic antiferromagnetic (SAF) structure. 
     
     
         8 . The non volatile memory cell according to  claim 7 , wherein the SAF structure comprises a first ferromagnetic layer, a second ferromagnetic layer and a nonmagnetic spacer layer between the first ferromagnetic layer and the second ferromagnetic layer. 
     
     
         9 . The non volatile memory cell according to  claim 8 , wherein the first ferromagnetic layer of the SAF structure is antiferromagnetically coupled to the recording layer of the MTJ stack. 
     
     
         10 . The non volatile memory cell according to  claim 8 , wherein the first ferromagnetic layer of the SAF structure is ferromagnetically coupled to the recording layer of the MTJ stack. 
     
     
         11 . The non volatile memory cell according to  claim 1 , wherein the recording layer comprises a material having a saturation magnetization of about 400 emu/cc to about 1300 emu/cc. 
     
     
         12 . The non volatile memory cell according to  claim 1 , wherein the stabilizing structure further comprises an upper reference layer, wherein the upper reference layer is positioned opposite the MTJ stack. 
     
     
         13 . The non volatile memory cell according to  claim 12  further comprising a tunnel barrier spacer layer, wherein the tunnel barrier spacer layer is positioned between the SAF structure and the upper reference layer. 
     
     
         14 . The non volatile memory cell according to  claim 13 , wherein the tunnel barrier spacer layer comprises magnesium oxide, magnesium nitride, magnesium oxynitride, alumina, tantalum oxide, titanium oxide, or combinations thereof 
     
     
         15 . The non volatile memory cell according to  claim 12  wherein the upper reference layer and the reference layer of the MTJ stack have parallel magnetic orientations. 
     
     
         16 . A non volatile memory cell comprising:
 a magnetic tunnel junction (MTJ) stack comprising:
 a reference layer; 
 a tunnel barrier; and 
 a recording layer having a thermal stability and comprising a material having a saturation magnetization of about 400 emu/cc to about 1300 emu/cc, 
 wherein the tunnel barrier is between the reference layer and the recording layer; 
   an exchange coupling spacer layer; and   a stabilizing structure,   wherein the exchange coupling spacer layer is between the STRAM structure and the stabilizing structure and exchange couples the recording layer of the STRAM structure to the stabilizing structure with a strength from about 50 to about 500 Oe, thereby increasing the thermal stability of the recording layer relative to a recording layer not exchange coupled to a stabilizing structure.   
     
     
         17 . The non volatile memory cell according to  claim 16 , wherein the MTJ stack has an aspect ratio of about 1. 
     
     
         18 . The non volatile memory cell according to  claim 16 , wherein the total thermal barrier factor (KuV/kT) of the recording layer is about 40 or more. 
     
     
         19 . A non volatile memory cell comprising:
 a magnetic tunnel junction (MTJ) stack comprising:
 a reference layer; 
 a tunnel barrier; and 
 a recording layer having a thermal stability and comprising a material having a saturation magnetization of about 400 emu/cc to about 1300 emu/cc, 
 wherein the tunnel barrier is between the reference layer and the recording layer; 
   an exchange coupling spacer layer comprising copper, tantalum, ruthenium, magnesium oxide, or combinations thereof; and   a stabilizing structure comprising a synthetic antiferromagnetic (SAF) structure,   wherein the exchange coupling spacer layer is between the STRAM structure and the stabilizing structure and exchange couples the recording layer of the STRAM structure to the stabilizing structure with a strength from about 50 to about 500 Oe, thereby increasing the thermal stability of the recording layer relative to a recording layer not exchange coupled to a stabilizing structure.   
     
     
         20 . The non volatile memory cell according to  claim 19 , wherein the MTJ stack has an aspect ratio of about 1.