Hemi-spherical grain silicon enhancement

Abstract

Hemi-spherical grain silicon enhancement with epitaxial silicon for semiconductor assemblies is described. Epitaxial silicon is used to enhance hemi-spherical grain silicon on semiconductor structures, such as storage node capacitor plates for a semiconductor assembly. Methods described include forming an optional amorphous silicon layer as a base to form hemi-spherical grain silicon thereon. The rough texture of the hemi-spherical grain silicon enhances the overall textured surface of the capacitor plate by the addition of epitaxial silicon.

1 . A method of forming a semiconductor assembly having a textured surfaced structure comprising: 
 forming hemi-spherical grain silicon over a supporting substrate; and 
 forming epitaxial silicon directly on the hemi-spherical grain silicon, wherein the epitaxial silicon has a non-uniform thickness across the outer surface of the hemi-spherical grain silicon;  
 wherein the non-uniform thickness across the outer surface of the hemi-spherical grain silicon forms an oblong outer surface of the epitaxial silicon.  
   
   
   
       2 . The method of  claim 1 , wherein the epitaxial silicon thickness varies in thickness up to approximately 100 Angstroms.  
   
   
       3 . The method of  claim 1 , wherein the textured surfaced structure is a capacitor structure.  
   
   
       4 . A method of forming a semiconductor assembly having textured surfaced structure comprising: 
 forming hemi-spherical grain silicon directly connecting to an underlying conductive material;    forming epitaxial silicon directly on an outer surface of the hemi-spherical grain silicon, wherein a thickness of the epitaxial silicon varies across the surface of the hemi-spherical grain silicon such that the epitaxial silicon has a greatest thickness at an apex of the hemi-spherical grain silicon;    wherein the non-uniform thickness across the outer surface of the hemi-spherical grain silicon forms an oblong outer surface of the epitaxial silicon.    
   
   
       5 . The method of  claim 4 , wherein the textured surfaced structure is a capacitor structure.  
   
   
       6 . The method of  claim 4 , wherein the epitaxial silicon thickness varies in thickness up to approximately 10 Angstroms.  
   
   
       7 . A semiconductor assembly having a textured surfaced structure comprising: 
 a hemi-spherical grain silicon over a supporting substrate; and    an epitaxial silicon directly on the hemi-spherical grain silicon, wherein the epitaxial silicon has a non-uniform thickness across the outer surface of the hemi-spherical grain silicon;    wherein an outer surface of the epitaxial silicon is oblong shaped.    
   
   
       8 . The semiconductor assembly of  claim 7 , wherein the epitaxial silicon thickness varies in thickness up to approximately 100 Angstroms.  
   
   
       9 . The semiconductor assembly of  claim 7 , wherein the textured surfaced structure is a capacitor structure.  
   
   
       10 . A semiconductor assembly having textured surfaced structure comprising: 
 a hemi-spherical grain silicon directly connecting to an underlying conductive material; and    an epitaxial silicon directly on an outer surface of the hemi-spherical grain silicon, wherein a thickness of the epitaxial silicon varies across the surface of the hemi-spherical grain silicon such that the epitaxial silicon has a greatest thickness at an apex of the hemi-spherical grain silicon;    wherein an outer surface of the epitaxial silicon is oblong shaped.    
   
   
       11 . The semiconductor assembly of  claim 10 , wherein the textured surfaced structure is a capacitor structure.  
   
   
       12 . The semiconductor assembly of  claim 10 , wherein the epitaxial silicon thickness varies in thickness up to approximately 100 Angstroms.