Solution for formation of organic thin film, and method for production thereof

Abstract

A solution for forming an organic metal thin film that can form rapidly a dense monomolecular film with less impurity. The solution for forming the organic thin film includes (A) at least one organic metal compound shown by the following formula (I) (provided that at least one organic metal compound contains a hydroxyl group); and (B) at least one organic metal compound shown by the following formula (II).

1 . A solution for forming an organic thin film, comprising at least one organic metal compound selected from the group consisting of:
 at least one organic metal compound of formula (III):   
       
         
           
           
               
               
           
         
         wherein:
 R 4 , R 5 , and R 6  each independently represents a hydrocarbon group with 1 to 30 carbons optionally having a substituent, or a halogenated hydrocarbon group with 1 to 30 carbons optionally having a substituent; 
 X 6 , X 7 , X 8 , X 9 , and X 10  each independently represents any one of R 4  to R 6 , a hydroxyl group, or a hydrolysable group; provided that not all of X 6 , X 7 , X 8 , X 9 , and X 10  are any one of R 4  to R 6 , and at least one of X 6 , X 7 , X 8 , X 9 , and X 10  represents a hydroxyl group and at least one of them represents a hydrolysable group; 
 when n2 is 2 or more, each R 5  and each X 8  may be the same or different; 
 M 3  represents at least one metal atom selected from the group consisting of Si, Ge, Sn, Ti, and Zr; and 
 n2 represents 0 or an integer of 1 or more; and 
 
         at least one cyclic organic metal compound of formula (IV): 
       
       
         
           
           
               
               
           
         
         wherein:
 R 7  represents a hydrocarbon group with 1 to 30 carbons optionally having a substituent, or a halogenated hydrocarbon group with 1 to 30 carbons optionally having a substituent; 
 X 11  represents R 7 , a hydroxyl group, or a hydrolysable group; provided that not all of X 11  are R 7 , and at least one of X 11  represents a hydroxyl group, and at least one of X 11  represents a hydrolysable group; 
 each R 7  and each X 11  may be the same or different; 
 M 4  represents at least one metal atom selected from the group consisting of Si, Ge, Sn, Ti, and Zr; and 
 n3 represents an integer of 2 or more. 
 
       
     
     
         2 . The solution for forming an organic thin film according to  claim 1 , wherein n2 is an integer of 0 to 3 in formula (III), and n3 is an integer of 2 to 5 in formula (IV). 
     
     
         3 . The solution for forming an organic thin film according to  claim 1 , wherein in at least one organic metal compound shown by formula (I) provided that at least one organic metal compound contains a hydroxyl group: 
       
         
           
           
               
               
           
         
         wherein:
 R 1  and R 2  represent a hydrocarbon group with 1 to 30 carbons optionally having a substituent, or a halogenated hydrocarbon group with 1 to 30 carbons optionally having a substituent; 
 X 1 , X 2 , X 3 , and X 4  each independently represents R 1 , R 2 , a hydroxyl group, or a hydrolysable group; provided that not all of X 1 , X 2 , X 3 , and X 4  are R 1  or R 2 ; 
 when n1 is 2 or more, each R 1  and each X 2  may be the same or different; 
 X 1  and X 4  may together form an oxygen atom, to form a ring wherein M 1  and oxygen atom are alternately bonded; 
 M 1  M represents at least one metal atom selected from the group consisting of Si, Ge, Sn, Ti, and Zr; and 
 n1 represents an integer of 1 or more; and 
 
         a total amount of the organic metal compound of formula (III) and the cyclic organic metal compound of formula (IV) is 30 to 95 mass %. 
       
     
     
         4 . The solution for forming an organic thin film according to  claim 1 , wherein the cyclic organic metal compound of formula (IV) is a main component in the mixture of the organic metal compound of formula (III) and the cyclic organic metal compound of formula (IV). 
     
     
         5 . A solution for forming an organic thin film comprising at least one organic metal compound of formula (I), provided that the at least one organic metal compound contains a hydroxyl group: 
       
         
           
           
               
               
           
         
         wherein:
 R 1  and R 2  represent a hydrocarbon group with 1 to 30 carbons optionally having a substituent, or a halogenated hydrocarbon group with 1 to 30 carbons optionally having a substituent; 
 X 1 , X 2 , X 3 , and X 4  each independently represents R 1 , R 2 , a hydroxyl group, or a hydrolysable group; provided that not all of X 1 , X 2 , X 3 , and X 4  are R 1  or R 2 ; each R 1  and each X 2  may be the same or different; 
 X 1  and X 4  may together form an oxygen atom, to form a ring wherein M 1  and oxygen atom are alternately bonded; 
 M 1  represents at least one metal atom selected from the group consisting of Si, Ge, Sn, Ti, and Zr; and 
 n1 represents an integer of 1 or more; 
 
         wherein a mass ratio of an organic metal compound in which n1=2 with respect to an organic metal compound in which n1=1 is greater than 0.5 in the organic metal compound of formula (I). 
       
     
     
         6 . The solution for forming an organic thin film according to  claim 5 , wherein n1 is an integer of 1 to 4. 
     
     
         7 . A method for producing a solution for forming an organic thin film, comprising a step of hydrolyzing and condensing at least one organic metal compound of formula (II):
   R 3   m M 2 X 5   4-m   (II)
   wherein:
 R 3  represents a hydrocarbon group with 1 to 30 carbons optionally having a substituent, or a halogenated hydrocarbon group with 1 to 30 carbons optionally having a substituent; 
 M 2  represents at least one metal atom selected from the group consisting of Si, Ge, Sn, Ti, and Zr; 
 X 5  represents a hydroxyl group or a hydrolysable group; and 
 m represents an integer of 1 to 3; 
   
       in an aliphatic ether solvent or an aliphatic ketone solvent, and in the presence of water and acid. 
     
     
         8 . The method for producing a solution for forming an organic thin film according to  claim 7 , wherein the solution for forming an organic thin film comprises:
 (A) at least one organic metal compound of formula (I), provided that the at least one organic metal compound contains a hydroxyl group:   
       
         
           
           
               
               
           
         
         wherein:
 R 1  and R 2  represent a hydrocarbon group with 1 to 30 carbons optionally having a substituent, or a halogenated hydrocarbon group with 1 to 30 carbons optionally having a substituent; 
 X 1 , X 2 , X 3 , and X 4  each independently represents R 1 , R 2 , a hydroxyl group, or a hydrolysable group; provided that not all of X 1 , X 2 , X 3 , and X 4  are R 1  or R 2 ; 
 when n1 is 2 or more, each R 1  and each X 2  may be the same or different; 
 X 1  and X 4  may together form an oxygen atom, to form a ring wherein M 1  and oxygen atom are alternately bonded; 
 M 1  represents at least one metal atom selected from the group consisting of Si, Ge, Sn, Ti, and Zr; and 
 n1 represents an integer of 1 or more; and 
 
         (B) the at least one organic metal compound of formula (II); 
         wherein an amount of (A) and (B) in the solution meets the following equations:
   40≦[( A )/{( A )+( B )}]×100≦100(mass %), and
 
   0≦[( B )/{( A )+( B )}]×100≦60(mass %).
 
 
       
     
     
         9 . The method for producing a solution for forming an organic thin film according to  claim 7 , wherein the aliphatic ether solvent is tetrahydrofuran or tetrahydropyran. 
     
     
         10 . The method for producing a solution for forming an organic thin film according to  claim 7 , wherein a pKa level of acid is 0 or less. 
     
     
         11 . The method for producing a solution for forming an organic thin film according to  claim 7 , wherein the acid is a solid acid. 
     
     
         12 . The method for producing a solution for forming an organic thin film according to  claim 7 , wherein the water is present in an amount of 0.1 to 20 mol with respect to 1 mol of organic metal compound of formula (II). 
     
     
         13 . The method for producing a solution for forming an organic thin film according to  claim 7 , further comprising a step of mixing at least one solvent selected from the group consisting of hydrocarbon solvent, fluorine solvent, and silicone solvent, after hydrolysis and condensation. 
     
     
         14 . The method for producing a solution for forming an organic thin film according to  claim 13 , wherein the solvent is mixed so that a concentration of the hydrolytic condensate of the organic metal compound of formula (II) becomes 0.01 to 20 mass %.