Method for forming a thin film and a thin film forming apparatus therefor

Abstract

A method for forming a thin film comprises the steps of: forming a first thin film using a raw material which comprises an adduct of metal β-diketonate and adduct-forming material by a metal organic chemical vapor deposition (MOCVD) method; associating metal β-diketonate dissociated from the adduct in the raw material with an adduct-forming material to regenerate the raw material; and forming a second thin film using the regenerated raw material by the MOCVD method.

What is claimed is:  
     
         1 . A method for forming a thin film, comprising the steps of: 
 forming a first thin film from a raw material which comprises an adduct of metal β-diketonate and adduct-forming material by a metal organic chemical vapor deposition (MOCVD) method;    associating metal β-diketonate dissociated from the adduct in the raw material with an adduct-forming material to regenerate the raw material; and    forming a second thin film using the regenerated raw material by the MOCVD method.    
     
     
         2 . A method for forming a thin film according to  claim 1 , wherein the metal β-diketonate is a metal dipivaloyl methanate.  
     
     
         3 . A method for forming a thin film according to  claim 2 , wherein the adduct-forming material comprises tetraethylenepentamine.  
     
     
         4 . A method for forming a thin film according to  claim 3 , wherein the associating step comprises the step of contacting a vapor of the adduct-forming material with a liquid of the residual raw material from the first thin film formation.  
     
     
         5 . A method for forming a thin film according to  claim 4 , wherein the metal comprises at least one of Ba and Sr.  
     
     
         6 . A method for forming a thin film according to  claim 4 , wherein the contacting step is performed while the liquid of the residual raw material is at a temperature lower than the temperature of the raw material or regenerated raw material during the first or second thin film forming step.  
     
     
         7 . A method for forming a thin film according to  claim 4 , wherein the contacting step is performed while the adduct-forming material has a vapor pressure which is higher than the vapor pressure of the raw material or regenerated raw material during the first or second thin film formation.  
     
     
         8 . A method for forming a thin film according to  claim 2 , wherein the metal comprises at least one of Ba and Sr.  
     
     
         9 . A method for forming a thin film according to  claim 1 , wherein the associating step comprises the step of contacting a vapor of the adduct-forming material with a liquid of the residual raw material from the first thin film formation.  
     
     
         10 . A method for forming a thin film according to  claim 9 , wherein the contacting step is performed while the liquid of the residual raw material is at a temperature lower than the temperature of the raw material or regenerated raw material during of the first or second thin film forming step.  
     
     
         11 . A method for forming a thin film according to  claim 9 , wherein the contacting step is performed while the adduct-forming material has a vapor pressure which is higher than the vapor pressure of the raw material or regenerated raw material during the first or second thin film formation.  
     
     
         12 . A method for forming a thin film according to  claim 1 , wherein during formation of the first and second thin films, the raw material and regenerated raw material are conveyed from a supply thereof to a MOCVD deposition chamber in combination with an inert carrier, and wherein during the association, the adduct-forming material is conveyed from a supply thereof to the supply of raw material in combination with an inert carrier.  
     
     
         13 . A method for forming a thin film according to  claim 1 , wherein an inert carrier is conveyed from a supply thereof to a supply of the raw material and regenerated raw material and during formation of the first and second thin films, the raw material and regenerated raw material are conveyed from the a supply thereof to a MOCVD deposition chamber in combination with the inert carrier, and wherein during the association, the adduct-forming material supply is isolated from the inert carrier supply.  
     
     
         14 . A thin film forming apparatus comprising: 
 a raw material container containing a supply of raw material comprising an adduct of metal β-diketonate and adduct-forming material;    an adduct-forming material container containing a supply of adduct-forming material and which container is communicated with the raw material container such that a vapor of the adduct-forming material is capable of being supplied to the raw material container; and    a MOCVD thin film deposition chamber communicated with the raw material container such that a vapor of raw material is capable of being supplied thereto from the raw material container.    
     
     
         15 . A thin film forming apparatus according to  claim 14 , wherein the metal β-diketonate is a metal dipivaloyl methanate.  
     
     
         16 . A thin film forming apparatus according to  claim 15 , further comprising a carrier gas supply separately communicated with both the raw material container and the adduct-forming material container, and a control adapted to permit (a) supply of the carrier gas via the adduct-forming material container to the raw material container or (b) supply of the carrier gas to the raw material container without passing through the adduct-forming material container.  
     
     
         17 . A thin film forming apparatus according to  claim 16 , further comprising a temperature sensor communicated with the raw material container and a temperature sensor communicated with the adduct-forming material container.  
     
     
         18 . A thin film forming apparatus according to  claim 16 , further comprising a vapor pressure sensor communicated with the raw material container and a vapor pressure sensor communicated with the adduct-forming material container.  
     
     
         19 . A thin film forming apparatus according to  claim 14 , further comprising a temperature sensor communicated with the raw material container and a temperature sensor communicated with the adduct-forming material container.  
     
     
         20 . A thin film forming apparatus according to  claim 14 , further comprising a vapor pressure sensor communicated with the raw material container and a vapor pressure sensor communicated with the adduct-forming material container.