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

A method for producing a composition for forming porous film comprising:

• preparing a reaction solution by hydrolysis and condensation, in the presence of acidic substance as catalyst, one or more silane compounds represented by Formulae (1) and (2):
• (R)aSi(OR1)4−a (1) (R2O)b(R3)4−bSi—R4—Si(OR5)c(R6)4−c (2)
• wherein, in Formula (1), R represents a straight-chain or branched alkyl group having 1 to 8 carbons or an aryl group wherein each group may have a substituent, and when two or more R's are present, the R's may be the same or different;
• R1 represents an alkyl group having 1 to 4 carbons, and when two or more R1's are present, the R1's may be the same or different;
• “a” represents an integer of from 0 to 3;
• and
• in Formula (2), R2 and R5 each independently represents an alkyl group having 1 to 4 carbons;
• R3 and R6 each independently represents a straight-chain or branched alkyl group having 1 to 8 carbons or an aryl group;
• b and c each represents an integer of 0 to 3;
• and R4 is selected from the group consisting of an oxygen atom;
• a phenylene group, —(CH2)d— wherein d is a integer of from 1 to 6 and, —{Si(R7)(R8)O}e— wherein R7 and R8 each independently represents an alkyl group having 1 to 6 carbons or an aryl group, and e is an integer of from 1 to 20;
• and
• subjecting the reaction solution to hydrolysis and condensation in the presence of a basic substance as a catalyst.

A semiconductor device having an internal porous film formed from a composition comprising a polymer solution obtained by hydrolysis and condensation of a reaction solution in the presence of a basic substance as catalysts, wherein the reaction solution has been produced by hydrolysis and condensation, in the presence of an acidic substance as catalyst, of one or more silane compounds selected from the group consisting of the compounds represented by Formulae (1) and (2):

• (R)aSi(OR1)4−a (1) (R2O)b(R3)4−bSi—R4—Si(OR5)c(R6)4−c (2)
• wherein, in Formula (1), R represents a straight-chain or branched alkyl group having 1 to 8 carbons or an aryl group in which each group may have a substituent, and when two or more R's are present, the R's may be the same or different;
• R1 represents an alkyl group having 1 to 4 carbons, and when two or more R1's are present, the R1's may be the same or different;
• “a” represents an integer of from 0 to 3;
• and
• in Formula (2), R2 and R5 each independently represents an alkyl group having 1 to 4 carbons;
• R3 and R6 each independently represents a straight-chain or branched alkyl group having 1 to 8 carbons or an aryl group;
• b and c each represents an integer of 0 to 3;
• and R4 is selected from the group consisting of an oxygen atom;
• a phenylene group, —(CH2)d— wherein d is a integer of from 1 to 6 and, —{Si(R7)(R8)O}e—wherein R7 and R8 each independently represents an alkyl group having 1 to 6 carbons or an aryl group, and e is an integer of from 1 to 20.