Porous film, composition and manufacturing method, interlayer dielectric film, and semiconductor device

Abstract

A porous film-forming composition comprising (A) a curable silicone resin having a Mn of at least 100, (B) a micelle-forming surfactant, and (C) a compound which generates an acid upon pyrolysis remains stable during storage. The composition is coated and heat treated to form a porous film which has flatness, uniformity, a low dielectric constant and a high mechanical strength so that it is best suited as an interlayer dielectric film in the fabrication of semiconductor devices.

1 . A porous film-forming composition comprising: 
 (A) 100 parts by weight of a curable silicone resin having a number average molecular weight of at least 100;    (B) 5 to 50 parts by weight of a micelle-forming surfactant; and    (C) 0.01 to 10 parts by weight of a compound which generates an acid upon pyrolysis.    
   
   
       2 . The composition of  claim 1 , wherein the curable silicone resin (A) comprises at least 10 mol % of structural units derived by hydrolytic condensation of a silane having the general formula (1):  
       SiZ 4    (1)  
     wherein Z is a hydrolyzable group or a partial hydrolytic condensate thereof.  
   
   
       3 . The composition of  claim 1 , wherein the compound (C) generates an acid upon pyrolysis at a pyrolytic temperature which is lower than the decomposition temperature or boiling point of the micelle-forming surfactant (B).  
   
   
       4 . The composition of  claim 3 , wherein the pyrolytic temperature of the compound (C) is up to 150° C.  
   
   
       5 . The composition of  claim 4 , wherein the compound (C) is a diazo compound of the general formula (3) or (4):  
     
       
         
         
             
             
         
       
     
     wherein R 1  and R 2  are each independently a substituted or unsubstituted monovalent hydrocarbon group.  
   
   
       6 . The composition of  claim 5 , wherein the diazo compound is selected from compounds of the formulae (5) to (10).  
     
       
         
         
             
             
         
       
     
   
   
       7 . The composition of  claim 1 , further comprising a solvent.  
   
   
       8 . A method of manufacturing a porous film, comprising: 
 a step of applying the composition of  claim 1  to a substrate to form a coating;    a first stage of heat treatment of the coating at a temperature which is lower than the decomposition temperature or boiling point of component (B) and equal to or higher than the pyrolytic temperature of component (C); and    a second stage of heat treatment of the coating at a temperature which is equal to or higher than the decomposition temperature or boiling point of component (B).    
   
   
       9 . A porous film obtained using the composition of  claim 1 .  
   
   
       10 . An interlayer dielectric film obtained using the composition of  claim 1.