Confined cell structures and methods of forming confined cell structures

Abstract

Techniques for reducing damage in memory cells are provided. Memory cell structures are typically formed using dry etch and/or planarization processes which damage certain regions of the memory cell structure. In one or more embodiments, certain regions of the cell structure may be sensitive to damage. For example, the free magnetic region in magnetic memory cell structures may be susceptible to demagnetization. Such regions may be substantially confined by barrier materials during the formation of the memory cell structure, such that the edges of such regions are protected from damaging processes. Furthermore, in some embodiments, a memory cell structure is formed and confined within a recess in dielectric material.

What is claimed is: 
     
         1 . A confined memory cell structure, comprising:
 a pinned region;   a free region; and   a barrier region having a horizontal portion and vertical portions, wherein the horizontal portion is formed between the pinned region and the free region, and wherein the vertical portions surround the periphery of the free region.   
     
     
         2 . The confined memory cell structure of  claim 1 , comprising dielectric materials, wherein the barrier region is formed along sidewalls of an opening in the dielectric materials and along a floor of the opening, wherein the floor of the opening exposes a portion of the pinned region. 
     
     
         3 . The confined memory cell structure of  claim 1 , wherein the pinned region and the free region each comprise Co, Fe, Ni or its alloys, NiFe, CoFe, CoNiFe, CoX, CoFeX, CoNiFeX (X═B, Cu, Re, Ru, Rh, Hf, Pd, Pt, C), Fe 3 O 4 , CrO 2 , NiMnSb and PtMnSb, BiFeO, or some combination of the above materials. 
     
     
         4 . The confined memory cell structure of  claim 1 , wherein the barrier region is suitable for physically separating the pinned region and the free region and suitable for substantially limiting coupling between a magnetization of the free region and a magnetization of the pinned region. 
     
     
         5 . The confined memory cell structure of  claim 1 , comprising a spacer region disposed around a periphery of the vertical portions of the barrier region. 
     
     
         6 . The confined memory cell structure of  claim 5 , comprising a contact disposed over the free region, wherein a periphery of the contact is directly adjacent to a sidewall of the barrier region. 
     
     
         7 . The confined memory cell structure of  claim 1 , wherein the confined memory cell structure comprises for a spin torque transfer magnetic random access memory (STT-MRAM) cell. 
     
     
         8 . A method of forming a confined memory cell structure, the method comprising:
 forming a pinned region;   forming a free region; and   forming a barrier region on the pinned region, such that a horizontal portion of the barrier region is formed between the pinned region and the free region, and wherein a vertical portion of the barrier region surrounds the periphery of the free region.   
     
     
         9 . The method of  claim 8 , wherein forming the barrier region comprises forming an opening within dielectric materials to expose at least a portion of the underlying pinned region and conformally depositing the barrier region within the opening such that the barrier region covers the at least a portion of the underlying pinned region and sidewalls of the opening. 
     
     
         10 . The method of  claim 9 , wherein forming the free region comprises depositing the free region on the barrier region within the opening. 
     
     
         11 . The method of  claim 10 , comprising forming a top lead on the free region. 
     
     
         12 . The method of  claim 11 , wherein forming the top lead comprises forming the top lead on the free region within the opening. 
     
     
         13 . The method of  claim 9 , wherein forming the opening within the dielectric materials comprises forming a via within the dielectric materials. 
     
     
         14 . A method of forming a confined memory cell structure, the method comprising:
 forming a pinned region;   depositing dielectric materials over the pinned region;   forming a via in the dielectric materials, wherein the via exposes a portion of the pinned region;   depositing barrier materials on sidewalls of the via and on the exposed portion of the pinned region to form a tunnel barrier in the via; and   forming a free region in the tunnel barrier, wherein portions of the tunnel barrier surround the periphery of the free region.   
     
     
         15 . The method of  claim 14 , wherein the pinned region and the free region each comprise ferromagnetic materials. 
     
     
         16 . The method of  claim 14 , wherein the magnetic memory cell structure comprises layers planar to a lateral direction and stacked in a longitudinal direction. 
     
     
         17 . The method of  claim 14 , comprising forming an antiferromagnetic region, wherein the pinned region is formed directly disposed over the antiferromagnetic region. 
     
     
         18 . The method of  claim 17 , wherein the antiferromagnetic region is positioned to achieve exchange coupling with the pinned region. 
     
     
         19 . The method of  claim 14 , comprising forming a conductive contact directly over the free region, such that the free region is substantially confined by the tunnel barrier and the conductive contact. 
     
     
         20 . The method of  claim 19 , wherein a portion of the conductive contact is in a recess surrounded by the tunnel barrier.