Method for forming ferroelectric film and semiconductor device

Abstract

In a method for forming a ferroelectric film of insulating metal oxide on a surface of an electrode with a concave or a convex or in convex shape which is formed above a substrate, multiple types of source gases constituting a material gas and each containing an organometallic compound are introduced into a chamber and main components of the multiple types of source gases are allowed to chemically react with one another with the chemical reaction proceeding depending on the reaction rate. Then, the ferroelectric film is deposited on the surface of the electrode.

1 - 10 . (canceled)  
   
   
       11 . A method for forming a ferroelectric film of insulating metal oxide on a surface of an electrode, the electrode having a concave or a convex or being of convex shape, the method comprising: 
 a first step of determining the temperature of a substrate and the pressure within a chamber serving as growth conditions of the ferroelectric film so that the ferroelectric film has a desired rate of step coverage over the electrode or more;    a second step of adjusting, at the substrate temperature and the chamber pressure determined by the first step, the proportion of a metal element constituting an A site of the ferroelectric film by changing the mixture ratio of multiple types of source gases which each contain an organometallic compound and which constitute a first material gas introduced into the chamber;    a third step of adjusting, under the condition in which the proportion of the metal element constituting the A site is kept constant, the proportion of a metal element constituting a B site of the ferroelectric film by changing the mixture ratio of multiple types of source gases which each contain an organometallic compound and which constitute a second material gas introduced into the chamber, thereby determining the proportions of components of the ferroelectric film; and    a fourth step of depositing the ferroelectric film on the surface of the electrode based on the film growth conditions determined in the first step and the proportions determined in the second and third steps.    
   
   
       12 . The method of  claim 11 , 
 wherein the first material gas comprises a gas mixture of a source gas containing Ta and a source gas containing Sr, and    the second material gas comprises a gas mixture of a source gas containing Bi and a source gas containing Sr.    
   
   
       13 . The method of  claim 11 , 
 wherein the first material gas comprises a gas mixture of a source gas containing Bi and a source gas containing La, and    the second material gas comprises a gas mixture of a source gas containing Ti and a source gas containing La.    
   
   
       14 . A method for forming a ferroelectric film of insulating metal oxide on a surface of an electrode, the electrode having a concave or a convex or being of convex shape, the method comprising: 
 a first step of determining the temperature of a substrate and the pressure within a chamber serving as growth conditions of the ferroelectric film so that the ferroelectric film has a desired rate of step coverage over the electrode or more;    a second step of adjusting, at the substrate temperature and the chamber pressure determined by the first step, the proportion of a metal element constituting a B site of the ferroelectric film by changing the mixture ratio of multiple types of source gases which each contain an organometallic compound and which constitute a first material gas introduced into the chamber;    a third step of adjusting, under the condition in which the proportion of the metal element constituting the B site is kept constant, the proportion of a metal element constituting an A site of the ferroelectric film by changing the mixture ratio of multiple types of source gases which each contain an organometallic compound and which constitute a second material gas introduced into the chamber, thereby determining the proportions of components of the ferroelectric film; and    a fourth step of depositing the ferroelectric film on the surface of the electrode based on the film growth conditions determined in the first step and the proportions determined in the second and third steps.    
   
   
       15 . The method of  claim 14 , 
 wherein the first material gas comprises a gas mixture of a source gas containing Bi and a source gas containing Sr, and    the second material gas comprises a gas mixture of a source gas containing Ta and a source gas containing Sr.    
   
   
       16 . The method of  claim 14 , 
 wherein the first material gas comprises a gas mixture of a source gas containing Ti and a source gas containing La and    the second material gas comprises a gas mixture of a source gas containing Bi and a source gas containing La.    
   
   
       17 - 19 . (canceled)