Phase change material memory device

Abstract

A lower electrode may be covered by a protective film to reduce the exposure of the lower electrode to subsequent processing steps or the open environment. As a result, materials that may have advantageous properties as lower electrodes may be utilized despite the fact that they may be sensitive to subsequent processing steps or the open environment.

1 . A memory comprising: 
 a lower electrode;    a protective layer over said electrode; and    a phase change material over said lower electrode.    
   
   
       2 . The memory of  claim 1  further comprising: 
 a support structure;    an insulator over said support structure, said insulator having an opening defined in said insulator;    a cup-shaped phase change material in said opening; and    a thermally insulating material in said cup-shaped phase change material.    
   
   
       3 . The memory of  claim 2  wherein said thermally insulating material fills said cup-shaped phase change material.  
   
   
       4 . The memory of  claim 1  wherein said phase change material is singulated.  
   
   
       5 . The memory of  claim 2  including a sidewall spacer in said singulated opening.  
   
   
       6 . The memory of  claim 5  wherein said electrode is located in said opening.  
   
   
       7 . The memory of  claim 6  wherein said cup-shaped phase change material is formed over said sidewall spacer.  
   
   
       8 . The memory of  claim 1  wherein said protective layer includes a material of the form Si x N y .  
   
   
       9 . The memory of  claim 8  wherein x is equal to three and y is equal to four.  
   
   
       10 . The memory of  claim 1  wherein said lower electrode is formed of carbon.  
   
   
       11 . The memory of  claim 1  including a base layer below said lower electrode.  
   
   
       12 . The memory of  claim 1  wherein said protective layer is an insulator.  
   
   
       13 . The memory of  claim 1  wherein said protective layer includes a central opening and said phase change material extends through said central opening to said lower electrode.  
   
   
       14 . A memory comprising: 
 a substrate;    a lower electrode formed over said substrate;    a phase change material covering a portion of said lower electrode; and    a protective layer extending over a portion of said lower electrode not covered by said phase change material.    
   
   
       15 . The memory of  claim 14  wherein said protective layer includes a central opening and said phase change material contacts said lower electrode through said central opening.  
   
   
       16 . The memory of  claim 14  including a base layer between said substrate and said lower electrode.  
   
   
       17 . The memory of  claim 16  wherein said base layer is conductive.  
   
   
       18 . The memory of  claim 14  wherein said lower electrode includes carbon.  
   
   
       19 . The memory of  claim 14  wherein said protective film is an electrical insulator.  
   
   
       20 . The memory of  claim 19  wherein said protective layer includes a material in the form Si x N y .