Replacement conductive hard mask for multi-step magnetic tunnel junction (mtj) etch

Abstract

A multi-step etch technique for fabricating a magnetic tunnel junction (MTJ) apparatus includes forming a first conductive hard mask on a first electrode of the MTJ apparatus for etching the first electrode during a first etching step. The method also includes forming a second conductive hard mask on the first conductive hard mask for etching magnetic layers of the MTJ apparatus during a second etching step. A spacer layer is conformally deposited on sidewalls of the first conductive hard mask. The second conductive hard mask is deposited on the first conductive hard mask and aligned with the spacer layer on the sidewalls of the first conductive hard mask.

What is claimed is: 
     
         1 . A method of fabricating a magnetic tunnel junction (MTJ) apparatus, comprising:
 conformally depositing a first spacer layer on a first conductive hard mask, on a first electrode layer, and on magnetic layers of the MTJ, a first portion of the first spacer layer being deposited on sidewalls of the first conductive hard mask and a second portion of the spacer layer being deposited on a surface of the first conductive hard mask;   selectively removing the second portion of the first spacer layer to create a recess within a dielectric layer, the recess being aligned with the first portion of the first spacer layer; and   filling the recess with a conductive material to form a second conductive hard mask on the first portion of the first spacer layer and on the first conductive hard mask.   
     
     
         2 . The method of  claim 1 , comprising depositing the first portion of the first spacer layer with a thickness less than the second portion of the first spacer layer. 
     
     
         3 . The method of  claim 1 , further comprising etching the magnetic layers of the MTJ in a pattern defined by the second conductive hard mask. 
     
     
         4 . The method of  claim 1 , further comprising depositing a first dielectric layer on the first spacer layer. 
     
     
         5 . The method of  claim 4 , further comprising planarizing the first dielectric layer to expose the second portion of first spacer layer. 
     
     
         6 . The method of  claim 5 , further comprising removing remaining portions of the first dielectric layer after filling the recess with the conductive material. 
     
     
         7 . The method of  claim 6 , further comprising removing third portions of the first spacer layer, the third portions of the first spacer layer abutting the magnetic layers of the MTJ where the magnetic layers are not overlapped by the second conductive hard mask. 
     
     
         8 . The method of  claim 7 , further comprising etching the magnetic layers of the MTJ in a pattern defined by the second conductive hard mask after removing the third portions of the first spacer layer. 
     
     
         9 . The method of  claim 1 , further comprising conformally depositing a second spacer layer over the second conductive hard mask, the second portion of the first spacer layer, the magnetic layers and the a second electrode layer. 
     
     
         10 . The method of  claim 9 , further comprising:
 depositing a second dielectric layer over the second spacer layer;   planarizing the second dielectric layer; and   forming a conductive interconnect in the second dielectric layer, the conductive interconnect forming a conductive path to the second conductive hard mask.   
     
     
         11 . The method of  claim 1 , further comprising integrating the MTJ apparatus into a mobile phone, a set top box, a music player, a video player, an entertainment unit, a navigation device, a computer, a hand-held personal communication systems (PCS) unit, a portable data unit, and/or a fixed location data unit. 
     
     
         12 . A method of fabricating a magnetic tunnel junction (MTJ) apparatus, comprising steps for:
 conformally depositing a first spacer layer on a first conductive hard mask, on a first electrode layer, and on magnetic layers of the MTJ, a first portion of the first spacer layer being deposited on sidewalls of the first conductive hard mask and a second portion of the spacer layer being deposited on a surface of the first conductive hard mask;   selectively removing the second portion of the first spacer layer to create a recess within a dielectric layer, the recess being aligned with the first portion of the first spacer layer; and   filling the recess with a conductive material to form a second conductive hard mask on the first portion of the first spacer layer and on the first conductive hard mask.   
     
     
         13 . The method of  claim 12 , further comprising steps for integrating the MTJ apparatus into a mobile phone, a set top box, a music player, a video player, an entertainment unit, a navigation device, a computer, a hand-held personal communication systems (PCS) unit, a portable data unit, and/or a fixed location data unit.