Method of fabricating a magnetoresistive bit from a magnetoresistive stack

Abstract

A method of fabricating a magnetoresistive bit from a magnetoresistive stack includes (a) etching through at least a portion of a thickness of the surface region to create a first set of exposed areas in the form of multiple strips extending in a first direction, and (b) etching through at least a portion of a thickness of the surface region to create a second set of exposed areas in the form of multiple strips extending in a second direction. The first set of exposed areas and the second set of exposed areas may have multiple areas that overlap. The method may also include, (c) after the etching in (a) and (b), etching through at least a portion of the thickness of the magnetoresistive stack through the first set and second set of exposed areas.

1 - 20 . (canceled) 
     
     
         21 . A magnetoresistive bit made from a magnetoresistive stack including at least two magnetic regions, an intermediate region positioned between the at least two magnetic regions, and a hard mask region, wherein the magnetoresistive bit is formed by a process comprising:
 (a) etching through at least a first layer of the hard mask region in a first direction to expose a first set of areas in a second layer of the hard mask region;   (b) after the etching in step (a), etching through at least the first layer of the hard mask region in a second direction to expose a second set of areas in the second layer of the hard mask region;   (c) after the etching in step (b), etching through at least the first layer of the hard mask region in the first direction to expose a third set of areas in the second layer of the hard mask region;   (d) after the etching in step (c), etching through at least the first layer of the hard mask region in the second direction to expose a fourth set of areas in the second layer of the hard mask region; and   (e) after the etching in step (d), etching through at least a portion of the thickness of the magnetoresistive stack through the first set, the second set, the third set, and the fourth set of areas.   
     
     
         22 . The magnetoresistive bit of  claim 21 , wherein the first direction is transverse to the second direction. 
     
     
         23 . The magnetoresistive bit of  claim 21 , wherein the first set of areas is spaced substantially equidistant from each other and the second set of areas is spaced substantially equidistant from each other. 
     
     
         24 . The magnetoresistive bit of  claim 21 , wherein the first set of areas is spaced substantially equidistant from each other and the third set of areas is spaced substantially equidistant from each other, the third set of areas being substantially equally spaced apart from the first set of areas. 
     
     
         25 . The magnetoresistive bit of  claim 21 , wherein
 each area of the first set of areas is positioned between two areas of the third set of areas, and   each area of the second set of areas is positioned between two areas of the fourth set of areas.   
     
     
         26 . The magnetoresistive bit of  claim 21 , wherein the first layer is disposed over the second layer and the first layer has a higher etch rate than the second layer. 
     
     
         27 . The magnetoresistive bit of  claim 21 , wherein the first layer having a higher etch rate to a chemical reagent is disposed over the second layer having a lower etch rate to the chemical reagent, and wherein the etching in steps (a)-(d) includes etching through the first layer of the hard mask region using an etching process that utilizes the chemical reagent. 
     
     
         28 . The magnetoresistive bit of  claim 21 , wherein the first layer having a higher etch rate to a chemical reagent is disposed over the second layer having a lower etch rate to the chemical reagent, and wherein the etching in steps (a)-(d) includes etching through the first layer of the hard mask region using chemical etching or a partially chemical etching, and the process further comprises etching through at least the second layer of the hard mask region using physical etching before the etching in step (e). 
     
     
         29 . The magnetoresistive bit of  claim 21 , wherein the first layer is disposed above the second layer, wherein the hard mask region further includes a third layer disposed below the second layer, and wherein the first and the third layers have a higher etch rate to a chemical reagent than the second layer. 
     
     
         30 . The magnetoresistive bit of  claim 21 , wherein the first direction is perpendicular to the second direction. 
     
     
         31 . A magnetoresistive bit made from a magnetoresistive stack including at least two magnetic regions, an intermediate region positioned between the at least two magnetic regions, and a hard mask region, wherein the magnetoresistive bit is formed by a process comprising:
 (a) etching through at least a first layer of the hard mask region in a first direction to expose a first set of areas in a second layer of the hard mask region;   (b) after the etching in step (a), etching through at least the first layer of the hard mask region in the first direction to expose a second set of areas in the second layer of the hard mask region;   (c) after the etching in step (b), etching through at least the first layer of the hard mask region in a second direction to expose a third set of areas in the second layer of the hard mask region;   (d) after the etching in step (c), etching through at least the first layer of the hard mask region in the second direction to expose a fourth set of areas in the second layer of the hard mask region; and   (e) after the etching in step (d), etching through at least a portion of the thickness of the magnetoresistive stack through the first set, the second set, the third set, and the fourth set of areas.   
     
     
         32 . The magnetoresistive bit of  claim 31 , wherein the first direction is transverse to the second direction. 
     
     
         33 . The magnetoresistive bit of  claim 31 , wherein the first set of areas includes multiple parallel strips spaced substantially equidistant from each other, and the second set of areas includes multiple parallel strips spaced substantially equidistant from each other. 
     
     
         34 . The magnetoresistive bit of  claim 31 , wherein the first set of areas are substantially equally spaced apart from the second set of areas. 
     
     
         35 . The magnetoresistive bit of  claim 31 , wherein each of the first set of areas is positioned between two of the second set of areas, and each of the fourth set of areas is positioned between two of the third set of areas. 
     
     
         36 . The magnetoresistive bit of  claim 31 , wherein the hard mask region includes a thickness in the range of approximately 600-1200 Å. 
     
     
         37 . The magnetoresistive bit of  claim 31 , wherein the first layer has a higher etch rate than the second layer. 
     
     
         38 . A magnetoresistive bit made from a magnetoresistive stack including at least two magnetic regions, an intermediate region positioned between the at least two magnetic regions, and a hard mask region, wherein the magnetoresistive bit is formed by a process comprising:
 (a) etching through the hard mask region in a first direction to create a first set of exposed areas;   (b) after the etching in step (a), etching through the hard mask region in a second direction to create a second set of exposed areas;   (c) after the etching in step (b), etching through the hard mask region in the first direction to create a third set of exposed areas;   (d) after the etching in step (c), etching through the hard mask region in the second direction to create a fourth set of exposed areas; and   (e) after the etching in step (d), etching through at least a portion of the thickness of the magnetoresistive stack through the first set, the second set, the third set, and the fourth set of exposed areas.   
     
     
         39 . The magnetoresistive bit of  claim 38 , wherein the hard mask region includes a first layer disposed over a second layer, wherein the first layer has a higher etch rate than the second layer. 
     
     
         40 . The magnetoresistive bit of  claim 38 , wherein the hard mask region includes a first layer having a higher etch rate to a chemical reagent disposed over a second layer having a lower etch rate to the chemical reagent, and wherein the etching in steps (a)-(d) includes etching through the first layer of the multi-layer hard mask region using an etching process that utilizes the chemical reagent.