Organo functionalized silane monomers and siloxane polymers of the same

Abstract

A thin film comprising a composition obtained by polymerizing a monomer having the formula I: wherein: R 1 is a hydrolysable group, R 2 is an organic crosslinking group, a reactive cleaving group or a polarizability reducing organic group, and R 3 is a bridging linear or branched bivalent hydrocarbyl group to form a siloxane material. The organo-functionalized molecule is capable of further reacting in the matrix so as to undergo cross-linking, cleaving or combination of both. The present invention provides excellent chemical resistance and very low chemical adsorption behavior due to high cross-linking bridging group density.

1 . A thin film comprising a composition obtained by polymerizing a monomer having the formula I:  
     
       
         
         
             
             
         
       
     
     wherein: 
 R 1  is a hydrolysable group,  
 R 2  is an organic crosslinking group, a reactive cleaving group or a polarizability reducing organic group, and  
 R 3  is a bridging linear or branched bivalent hydrocarbyl group.  
 to form a siloxane material.  
 
   
   
       2 . The thin film according to  claim 1 , wherein independently 
 R 1  is selected from the group of hydrogen, halides, alkoxy and acyloxy groups,    R 2  is selected from alkyl groups, alkenyl groups and aryl groups, and    R 3  is selected from linear and branched alkylene groups, alkenylene groups, alkynylene groups, bivalent alicyclic groups, bivalent polycyclic groups, and bivalent aromatic groups.    
   
   
       3 . The thin film according to  claim 1 , wherein the composition comprises a cross-linked poly(organosiloxane).  
   
   
       4 . The thin film according to any of  claims 1  to  3 , wherein the composition is obtained essentially by homopolymerization of monomers having formula I.  
   
   
       5 . The thin film according to any of  claims 1  to  3 , wherein the composition is obtained by copolymerizing first monomers having formula I, wherein R 3  stands for a linear bivalent hydrocarbyl residue, with second monomers having formula I, wherein R 3  stands for a branched bivalent hydrocarbyl residue, the molar ratio of the first monomers to the second monomers is 95:5 to 5:95, in particular 90:10 to 10:90, preferably 80:20 to 20:80.  
   
   
       6 . The thin film according to any of the preceding claims, comprising a cured thin layer of the poly(organosiloxane) having a thickness of 0.01 to 50 um, in particular 0.5 to 5 um, preferably from 1 to 3 un.  
   
   
       7 . The thin film according to any of the preceding claims, having a density of at least 1.2 g/cm 3 , preferably 1.45 g/cm 3  or more, more preferably 1.60 g/cm 3  or more, in particular up to about 2.5 g/cm 3 .  
   
   
       8 . The thin film according to any of the preceding claims, having either or both of the following properties: 
 a glass transition temperature, which is higher than 200° C., in particular 400° C. or more, in particular 500° C. or more, and    a dielectric constant of 3.0 or less, in particular 2.9 or less, preferably about 2.5 to 1.9.    
   
   
       9 . The thin film according to any of the preceding claims, having a coefficient of thermal expansion of 12-22 ppm, preferably about 15-20 ppm.  
   
   
       10 . The thin film according to any of the preceding claims, comprising an organosiloxane material having a (weight average) molecular weight of from 500 to 100,000 g/mol.  
   
   
       11 . The thin film according to any of the preceding claims, comprsing an organosiloxane material, which has a repeating -M-O-M-O- backbone having a first organic substituent bound to the backbone, the material having a molecular weight of from 500 to 100,000 g/mol, where M is silicon and O is oxygen, and the film exhibiting one or several of the following properties: 
 a k value of 2.9 or less or even more preferably 2.5 or less,    a CTE 30 ppm or less, and    Young's modulus 4 GPa or more.    
   
   
       12 . An object comprising a low k dielectric film, the film comprising a material according to any of  claims 1  to  10 .  
   
   
       13 . A method of forming a thin film having a dielectric constant of 2.9 or less, comprising 
 polymerizing a monomer having the formula I:                          wherein R 1 , R 2  and R 3  have the same meaning as above, to form a siloxane material;    depositing the siloxane material in the form of a thin layer; and    curing the thin layer to form a film.    
   
   
       14 . The method according to  claim 13 , comprising 
 homopolymerizing a monomer having the formula I or copolymerizing isomers thereof in a liquid medium formed by a first solvent to form a hydrolyzed product comprising a siloxane material;    depositing the hydrolyzed product on the substrate as a thin layer; and    curing the thin layer to form a thin film having a thickness of 0.01 to 10 um.    
   
   
       15 . The method according to  claim 13  or  14 , comprising 
 homopolymerizing a monomer having the formula I or copolymerizing isomers thereof in a liquid medium formed by a first solvent to form a hydrolyzed product comprising a siloxane material;    recovering the hydrolyzed product;    mixing the hydrolyzed product with a second solvent to form a solution;    applying the solution on a substrate;    removing the second solvent to deposit the hydrolyzed product on the substrate as a thin layer; and    curing the thin layer to form a thin film having a thickness of 0.01 to 10 um.    
   
   
       16 . The method according to  claim 14  or 15, comprising carrying out the step of homopolymerising to form a polymerized product and the step of curing the hydrolyzed product at a temperature of 50 to 425° C.  
   
   
       17 . The method according to any of  claims 13  to  16 , comprising 
 depositing the siloxane material on a substrate of a semiconductor device; and    patterning the siloxane material to form a dielectric in a semiconductor device.    
   
   
       18 . The method according to  claim 17 , comprising 
 patterning the siloxane material by removing siloxane material in selected areas and    depositing an electrically conductive material in the selected areas.    
   
   
       19 . The method according to  claim 18 , wherein a barrier layer is deposited in the selected areas prior to depositing the electrically conductive material.  
   
   
       20 . The method according to  claim 18 , wherein the electrically conductive material is deposited in the selected areas without a barrier layer, and wherein the electrically conductive material comprises aluminum or copper.  
   
   
       21 . The method according to  claim 13 , comprising 
 carrying our polymerization at conditions conducive to cross-linking between the monomer units so as to form a siloxane material;    depositing the siloxane material on a substrate;    heating the siloxane material to cause further cross-linking;    patterning the siloxane material to remove siloxane material in selected areas;    adding an electrically conductive material in the selected areas; and    performing chemical mechanical polishing on the electrically conductive material down to the siloxane material.    
   
   
       22 . The method according to  claim 21 , wherein the siloxane material is patterned by selectively exposing the siloxane material to electromagnetic energy and removing non-exposed areas of siloxane material with a developer.  
   
   
       23 . The method according to  claim 22 , wherein the siloxane material is patterned by RIE.  
   
   
       24 . The method according to any of  claims 21  to  23 , wherein the patterning is performed without a capping layer.  
   
   
       25 . The method according to any of  claims 13  to  24 , wherein the siloxane material is deposited on a substrate of a semiconductor device, and the siloxane material is heated to cause further cross-linking, whereby a film is obtained, having a shrinkage after heating of less than 10%, preferably less than 5%, in particular less than 2%, and a thermal stability of more 425° C.  
   
   
       26 . The method according to any of  claims 13  to  25 , wherein the compound of formula I is obtained from a compound of formula I wherein R 2  stands for hydrogen and R 1  and R 3  have the same meanings as above.  
   
   
       27 . The method according to  claim 26 , wherein the compound of formula I, wherein R 2  stands for hydrogen, is selectively produced by hydrosilylation of halosubstituted silanes in the presence of a cobalt octoate catalyst.  
   
   
       28 . The method according to any of  claims 13  to  27 , wherein the film is baked after spin coating at a temperature below about 200° C. and then cured by exposure to UV radiation simultaneously with a thermal treatment at a temperature below 450° C. for 0.1 to 20 minutes.  
   
   
       29 . The method according to  claim 28 , wherein the curing is carried out for a sufficient period of time for reacting the organic substitutent at position R 2  of the unit derived from a monomer having the formula I above.  
   
   
       30 . A method of producing silane-based materials by hydrosilylation, wherein the reaction is carried out in the presence of cobalt octacarbonyl as a catalyst.  
   
   
       31 . The method according to  claim 30 , wherein a trihalosilane is reacted with a dihalosilane in the presence of cobalt octacarbonyl.  
   
   
       32 . The method according to  claim 30  or  31 , wherein a trihalosilane is used having a reactive organic group comprising an unsaturated bond.  
   
   
       33 . The method according to  claim 31  or  32 , wherein vinyltrichlorosilane is reacted with dichlorosilane to form 1,1,1,4,4-pentachloro-1,4-disilabutane.