Fine particle-containing body, fine-particle-containing body manufacturing method, storage element, semiconductor device and electronic equipment

Abstract

A silicon oxide of a film thickness of about 50 nm is formed on a surface of a silicon substrate by thermal oxidation. Silver is implanted into the silicon oxide with implantation energy of about 30 keV by a negative ion implantation method. By subjecting the silicon oxide, into which the silver has been implanted, to heat treatment at a temperature of not lower than 200° C. and lower than the melting point of silver, silver particles are formed. By oxidizing the surface portions of the fine particles by heat treatment in an oxidizing atmosphere, silver oxide is formed as a coating layer.

1 . A fine particle-containing body comprising: 
 a first layer;    a second layer;    a medium that is formed between the first layer and the second layer and made of a first material;    one or more fine particles that are located in the medium and are made of a second material; and    a coating layer that covers said or each fine particle and is made of a third material,    the second material being a material that has a function to retain an electric charge, and    the third material being a material whose electrical conductivity is lower than that of the second material.    
   
   
       2 . The fine particle-containing body as claimed in  claim 1 , wherein 
 the coating layer that covers said fine particle or at least one of said fine particles partially protrudes from the medium.    
   
   
       3 . The fine particle-containing body as claimed in  claim 1 , wherein 
 the coating layer that covers said fine particle or at least one of said fine particles is partially in contact with at least one of the first and second layers.    
   
   
       4 . The fine particle-containing body as claimed in  claim 1 , wherein 
 said fine particle or at least one of said fine particles is connected to a path that connects the fine particle with the first or second layer not by way of the medium.    
   
   
       5 . The fine particle-containing body as claimed in  claim 1 , wherein 
 at least two of said fine particles are connected to a path that connects the fine particles with each other not by way of the medium.    
   
   
       6 . The fine particle-containing body as claimed in  claim 1 , wherein 
 said fine particle or at least one of said fine particles has a roughly spherical shape, and    the roughly spherical fine particle has a ratio of a distance from a center of gravity to an outer peripheral surface portion located farthest from the center of gravity with respect to a distance from the center of gravity to an outer peripheral surface portion located nearest to the center of gravity, the ratio being not smaller than 1.0 and not greater than 1.5.    
   
   
       7 . The fine particle-containing body as claimed in  claim 1 , wherein 
 an energy gap between a lower end of a conduction band of the second material and a vacuum level is greater than an energy gap between a lower end of a conduction band of the third material and the vacuum level.    
   
   
       8 . The fine particle-containing body as claimed in  claim 1 , wherein 
 an energy gap between an upper end of a valence band of the second material and a vacuum level is smaller than an energy gap between an upper end of a valence band of the third material and the vacuum level.    
   
   
       9 . The fine particle-containing body as claimed in  claim 1 , wherein 
 the first material is a silicon oxide or a silicon nitride,    the second material is a semiconductor or a metal, and    the third material is a semiconductor oxide or a metal oxide.    
   
   
       10 . The fine particle-containing body as claimed in  claim 1 , wherein 
 the second material is hafnium, and    the third material is a hafnium oxide.    
   
   
       11 . A method for manufacturing the fine particle-containing body claimed in  claim 1 , comprising: 
 forming the medium on the first or second layer;    introducing a substance for forming at least one fine particle in the medium;    forming the fine particle from the substance introduced into the medium; and    reforming a surface portion of the fine particle,    the method further comprising removing a portion from a surface of the medium to a prescribed depth after introducing the substance for forming the fine particle into the medium.    
   
   
       12 . A method for manufacturing the fine particle-containing body claimed in  claim 1 , comprising: 
 introducing a substance for forming at least one fine particle into a precursor of the medium;    reforming a part of the precursor into which the substance has been introduced;    removing the reformed portion of the precursor; and    reforming a portion other than the removed portion of the precursor.    
   
   
       13 . A method for manufacturing the fine particle-containing body claimed in  claim 1 , comprising: 
 forming a control layer for controlling introduction of a substance for forming at least one fine particle on a surface of a precursor of the medium;    introducing the substance for forming the fine particle into the precursor of the medium via the control layer;    forming the fine particle from the substance introduced into the precursor;    removing the control layer; and    reforming the precursor from which the control layer is removed.    
   
   
       14 . A storage element comprising a field effect transistor formed by employing the fine particle-containing body claimed in  claim 1 .  
   
   
       15 . A semiconductor device comprising a memory circuit integrated with the storage element claimed in  claim 14 .  
   
   
       16 . Electronic equipment comprising the semiconductor device claimed in  claim 15.