Semiconductor memory device and method of manufacturing the same

Abstract

The semiconductor memory device according to the present invention includes a charge storage layer 26 formed over a semiconductor substrate 10 and including a plurality of particles 16 as charge storage bodies in insulating films 12, 24 , and a gate electrode 30 formed over the charge storage layer 26 , in which the particles 16 are formed of metal oxide or metal nitride.

1 . A method of manufacturing a semiconductor memory device comprising the steps of:
 forming a first insulating film over a semiconductor substrate;   forming a metal compound film of a metal oxide or a metal nitride over the first insulating film;   self-cohering the metal compound film by a thermal processing to form a plurality of particles of the metal oxide or the metal nitride;   forming a second insulating film over the first insulating film with the particles formed on; and   forming a gate electrode over the second insulating film.   
     
     
         2 . The method of manufacturing a semiconductor memory device according to  claim 1 , wherein
 after the step of forming the insulating film, the step of forming the metal compound film to the step of forming the second insulating film are repeated.   
     
     
         3 . The method of manufacturing a semiconductor memory device according to  claim 1 , wherein
 a particle diameter of the particles is controlled by a film thickness of the metal compound film.   
     
     
         4 . The method of manufacturing a semiconductor memory device according to  claim 1 , wherein
 in the step of forming the metal compound film, the metal compound film is formed in amorphous state.   
     
     
         5 . The method of manufacturing a semiconductor memory device according to  claim 1 , wherein
 the metal compound film is a film containing hafnium oxide as an ingredient.   
     
     
         6 . A method of manufacturing a semiconductor memory device comprising the steps of:
 forming a first insulating film over a semiconductor substrate;   forming a metal compound film of metal oxide or metal nitride over the first insulating film;   forming a second insulating film over the metal compound film;   self-cohere the metal compound film by a thermal processing to form a plurality of particles of the metal oxide or the metal nitride; and   forming a gate electrode over the second insulating film.   
     
     
         7 . The method of manufacturing a semiconductor memory device according to  claim 6 , wherein
 after the step of forming the second insulating film, the step of forming the metal compound film and the step of forming the second insulating film are repeated.   
     
     
         8 . The method of manufacturing a semiconductor memory device according to  claim 6 , wherein
 a particle diameter of the particles is controlled by a film thickness of the metal compound film.   
     
     
         9 . The method of manufacturing a semiconductor memory device according to  claim 6 , wherein
 in the step of forming the metal compound film, the metal compound film is formed in amorphous state.   
     
     
         10 . The method of manufacturing a semiconductor memory device according to  claim 6 , wherein
 the metal compound film is a film containing hafnium oxide as an ingredient.