Semiconductor device and method for manufacturing the same

Abstract

A semiconductor device comprises a lower electrode shaped as a convex formed on a semiconductor substrate having crystals, a grain boundary between adjacent crystals being perpendicular to a side of the lower electrode, a capacitor insulating film covering the lower electrode, and an upper electrode formed on the capacitor insulating film.

1 . A semiconductor device comprising: 
 a lower electrode shaped as a convex formed on a semiconductor substrate, said lower electrode having crystals, a grain boundary between adjacent crystals being perpendicular to a side of the lower electrode;    a capacitor insulating film covering the lower electrode; and    an upper electrode formed on the capacitor insulating film.    
   
   
       2 . A semiconductor device according to  claim 1 , wherein the crystals, with the grain boundary between adjacent crystals being perpendicular to a side of the lower electrode, constitute the side of the lower electrode.  
   
   
       3 . A semiconductor device according to  claim 1 , wherein at least part of the grain boundary on the side of the lower electrode has a direction same as that of a grain boundary of the capacitor insulating film.  
   
   
       4 . A semiconductor device according to  claim 3 , further comprising at least one cap film, made of an insulating material other than the capacitor insulating film, between at least an end portion of the a top surface of the lower electrode and the capacitor insulating film.  
   
   
       5 . A semiconductor device according to  claim 3 , wherein the side of the lower electrode is continuous to a side of the cap film.  
   
   
       6 . A semiconductor device according to  claim 1 , a lower end portion of the side of the lower electrode is covered by an insulating film.  
   
   
       7 . A semiconductor device according to  claim 1 , wherein the capacitor insulating film formed on a top surface of the lower electrode has a thickness greater than that of the capacitor insulating film formed on the side of the lower electrode.  
   
   
       8 . A semiconductor device according to  claim 1 , wherein the lower electrode is used as a memory cell of a stack-type DRAM.  
   
   
       9 . A semiconductor device according to  claim 1 , wherein the capacitor insulating film is made of an oxide containing Sr and Ti.  
   
   
       10 - 23 . (canceled)