Composition for forming porous film, porous film and method for forming the same, interlevel insulator film, and semiconductor device

Abstract

Provided are a composition for forming porous film which can form a porous film having practical mechanical strength in a simple and low cost process; a porous film and a method for forming the film; and an inexpensive, high-performing and highly reliable semiconductor device comprising the porous film inside. More specifically, provided is a composition for forming porous film, comprising a polymer which is obtainable by hydrolyzing and condensing one or more silane compounds represented by Formula (1), or preferably by hydrolyzing and co-condensing one or more silane compounds represented by Formula (1) and one more silane compounds represented by Formula (2), Formulas (1) and (2) being: (R 1 ) a Si(R 2 ) 4-a   (1) (R 3 ) b Si(R 4 ) 4-b   (2) Also provided is a method for forming porous film comprising a step of applying said composition on a substrate to form film and a step of transforming the film into porous film.

1 - 9 . (canceled)  
     
     
         10 . A porous film prepared from a composition comprising: 
 an acid or base generator for generating an acid or a base by its thermal decomposition; and    a polymer which is obtainable by hydrolyzing and condensing one or more silane compounds represented by Formula (1):     (R 1 ) a Si(R 2 ) 4-a   (1)   wherein R 1  represents a straight chain or branched monovalent hydrocarbon having 6 to 20 carbons which may be substituted or unsubstituted and when there are R 1 s the R 1 s each may be independently same or different; R 2  represents a hydrolysable group and when there are R 2 s, the R 2 s each may be independently same or different; and a is an integer of 1 to 3.    
     
     
         11 . The porous film according to  claim 10  wherein the film is an interlevel insulator film.  
     
     
         12 . A semiconductor device comprising an internal porous film formed by a composition comprising an acid or base generator for generating acid or base by its thermal decomposition and a polymer prepared from one or more silane compounds.  
     
     
         13 . The semiconductor device according to  claim 12  wherein said polymer is obtainable prepared by hydrolyzing and condensing one or more silane compounds represented by Formula (1): 
         (R 1 ) a Si(R 2 ) 4-a   (1) 
       wherein R 1  represents a straight chain or branched monovalent hydrocarbon having 6 to 20 carbons which may be substituted or unsubstituted and when there are R 1 s, the R 1 s each may be independently same or different; R 2  represents a hydrolysable group and when there are R 2 s, the R 2 s each may be independently same or different; and a is an integer of 1 to 3.  
     
     
         14 . The semiconductor device according to  claim 12  wherein said polymer is prepared by hydrolyzing and co-condensing one or more silane compounds represented by Formula (1) and one more silane compounds represented by Formula (2), Formulas (1) and (2) being: 
         (R 1 ) a Si(R 2 ) 4-a   (1) (R 3 ) b Si(R 4 ) 4-b   (2) 
       wherein R 1  represents a straight chain or branched monovalent hydrocarbon having 6 to 20 carbons which may be substituted or unsubstituted and when there are R 1 s, the R 1 s each may be independently same or different; R 2  represents a hydrolysable group and when there are R 2 s, the R 2 s each may be independently same or different; and a is an integer of 1 to 3; R 3  represents a straight chain or branched monovalent hydrocarbon having 1 to 5 carbons which may be substituted or unsubstituted and when there are R 3 s, the R 3 s each may be independently same or different; R 4  represents a hydrolysable group and when there are R 4 s, the R 4 s each may be independently same or different; and b is an integer of 0 to 3.  
     
     
         15 . The semiconductor device according to  claim 14  wherein said polymer is a silanol group-containing hydrolysate having number-average molecular weight of 100 or more, and in said polymer 30 to 80 mol % of structural units derived from said silane compound represented by Formula (2) is represented by Formula (3): 
         Si(OH) c (R 5 ) 4-c   (3) 
       wherein R 5  represents a siloxane residue or R 3 , and c is an integer of 1 or 2.  
     
     
         16 . The semiconductor device according to  claim 13  wherein the decomposition temperature of said acid or base generator is lower than the decomposition temperature of R 1  of said polymer.  
     
     
         17 . The semiconductor device according to  claim 16  wherein said acid or base generator has a decomposition temperature of 250° C. or less.  
     
     
         18 . The semiconductor device according to  claim 17  wherein said acid or base generator is a diazo compound represented by Formula (4) or (5):  
       
         
           
           
               
               
           
         
       
       wherein R and R′ each independently represents an alkyl group, an aromatic group, an aralkyl group or a fluoroalkyl group and R and R′ may be same or different.  
     
     
         19 . The semiconductor device according to  claim 12  wherein said porous film is between metal interconnections in a same layer of multi-level interconnects, or is between upper and lower metal interconnection layers.  
     
     
         20 . The porous film according to  claim 10  wherein the decomposition temperature of the acid or base generator is lower than the decomposition temperature of R 1  of said polymer.  
     
     
         21 . The porous film according to  claim 20  wherein the acid or base generator has decomposition temperature of 250° C. or less.  
     
     
         22 . The porous film according to  claim 21  wherein said acid or base generator is a diazo compound represented by Formula (4) or (5):  
       
         
           
           
               
               
           
         
       
       wherein R and R′ each independently represents an alkyl group, an aromatic group, an aralkyl group or a fluoroalkyl group and R and R′ may be same or different.  
     
     
         23 . A porous film comprising: 
 an acid or base for generating an acid or a base by its thermal decomposition; and    a polymer which is prepared by hydrolyzing and co-condensing one or more silane compounds represented by Formula (1) and one more silane compounds represented by Formula (2), Formulas (1) and (2) being:     (R 1 ) a Si(R 2 ) 4-a   (1) (R 1 ) b Si(R 4 ) 4-b   (2)   wherein R 1  represents a straight chain or branched monovalent hydrocarbon having 6 to 20 carbons which may be substituted or unsubstituted and when there are R 1 s, the R 1 s each may be independently same or different; R 2  represents a hydrolysable group and when there are R 2 s, the R 2 s each may be independently same or different; and a is an integer of 1 to 3; R 3  represents a straight chain or branched monovalent hydrocarbon having 1 to 5 carbons which may be substituted or unsubstituted and when there are R 3 s, the R 3 s each may be independently same or different; R 4  represents a hydrolysable group and when there are R 4 s, the R 4 s each may be independently same or different; and b is an integer of 0 to 3.    
     
     
         24 . The porous film according to  claim 23  wherein said polymer is a silanol group-containing hydrolysate having number-average molecular weight of 100 or more, and in said polymer 30 to 80 mol % of structural units derived from said silane compound represented by Formula (2) is represented by Formula (3): 
         Si(OH) c (R 5 ) 4-c   (3) 
       wherein R 5  represents a siloxane residue or R 3 , and c is an integer of 1 or 2.  
     
     
         25 . The porous film according to  claim 23  wherein the decomposition temperature of the acid or base generator is lower than the decomposition temperature of R 1  of said polymer.  
     
     
         26 . The porous film according to  claim 25  wherein the acid or base generator has decomposition temperature of 250° C. or less.  
     
     
         27 . The porous film according to  claim 26  wherein said acid or base generator is a diazo compound represented by Formula (4) or (5):  
       
         
           
           
               
               
           
         
       
       wherein R and R′ each independently represents an alkyl group, an aromatic group, an aralkyl group or a fluoroalkyl group and R and R′ may be same or different.  
     
     
         28 . The porous film according to  claim 23  wherein the film is an interlevel insulator film.