Low k dielectric

Abstract

A spin-on dielectric of novel composition formed as a sol comprising an a source of silicon such as an orthosilicate ester, alone or in combination with an alkylated orthosilicate ester, a polar solvent, water, an acid catalyst, which may be a strong acid catalyst, and an amphiphilic block copolymer surfactant, optionally including an organic acid, a co-solvent and/or a reactive solvent. Also provided is a method of formulating the sol, a film made from the spin-on dielectric that has desirable electrical and mechanical properties, methods for treating the film described to optimize the film's electrical and mechanical performance, and methods for depositing the film onto silicon, steel or other surfaces.

1 - 32 . (canceled) 
     
     
         33 . A method of formulating a dielectric film, comprising
 combining a silica source, polar solvent, water, acid catalyst, polymer surfactant, and cosolvent to form a single component colloidal solution.   
     
     
         34 . The method of formulating a dielectric film of  claim 33 , wherein the solution has a shelf life of at least 6 months. 
     
     
         35 . A method of formulating a dielectric film, comprising:
 combining a silica source with a polar solvent to form a part A;   separately combining water, an acid catalyst, and a polymer surfactant with a polar solvent to form a part B; and   mixing part A and part B to form a fluid colloidal solution.   
     
     
         36 . The method of  claim 35  in which part A and part B are kept separate prior to mixing. 
     
     
         37 . The method of  claim 35 , in which part A and part B have shelf lives of at least 6 months prior to mixing. 
     
     
         38 . The method of  claim 35 , in which the silica source is thoroughly hydrolyzed prior to formulation with the other components. 
     
     
         39 . The method of  claim 35  in which residual water and solvent are removed by distillation and replaced with fresh solvent. 
     
     
         40 . The method of  claim 39  in which the fresh solvent is a different solvent. 
     
     
         41 . The method of  claim 39  in which the fresh solvent is a cosolvent. 
     
     
         42 . A method for preparing a low dielectric film, comprising:
 combining a silica source, polar solvent, water, acid catalyst, polymer surfactant, and cosolvent to form a single component colloidal solution, and   depositing the fluid colloidal solution onto a surface under conditions whereby to form a low dielectric film.   
     
     
         43 . The method of  claim 42  further comprising adding a cosolvent. 
     
     
         44 . The method of  claim 42 , wherein the step of adding a cosolvent is completed at the time of manufacturing the film, or done later in part. 
     
     
         45 . (canceled) 
     
     
         46 . A method for preparing a low dielectric film, comprising:
 combining a silica source with a polar solvent to form a part A;   separately combining water, an acid catalyst, and a polymer surfactant with a polar solvent to form a part B;   mixing part A and part B to form a fluid colloidal solution; and   depositing the fluid colloidal solution onto a surface under conditions whereby to form a low dielectric film.   
     
     
         47 . The method of  claim 46  in which the fluid colloidal solution is heated to at least 40° C. for at least one hour prior to depositing it onto the surface. 
     
     
         48 . The method of  claim 46  in which the fluid colloidal solution is deposited on the surface by spinning onto a silicon wafer. 
     
     
         49 . The method of  claim 48  where the film is annealed by an electron beam. 
     
     
         50 . The method of  claim 46  in which the film is soft baked at 130-150° C. 
     
     
         51 . The method of  claim 50  in which the film is exposed to a reactive gas before or during bake. 
     
     
         52 . The method of  claim 51  in which the reactive gas is water vapor. 
     
     
         53 . The method of  claim 51  in which the reactive gas is ammonia vapor. 
     
     
         54 . The method of  claim 48  in which the film is exposed to UV illumination during soft bake. 
     
     
         55 . The method of  claim 48  in which the film is annealed at 200-450° C. 
     
     
         56 . The method of  claim 55  in which the film is annealed at 250° C. in the presence of a reducing atmosphere that contains hydrogen. 
     
     
         57 . The method of  claim 56  in which the film is exposed to UV illumination before being annealed. 
     
     
         58 . The method of  claim 56  in which the film is exposed to UV illumination during anneal. 
     
     
         59 . The method of  claim 58  in which the film is exposed to UV illumination at a wavelength or wavelengths between 170 nm and 365 nm during anneal. 
     
     
         60 . The method of  claim 55  in which the annealing is done in air. 
     
     
         61 . The method of  claim 55  in which the annealing is done in nitrogen or argon. 
     
     
         62 . The method of  claim 55  in which the annealing is done in helium. 
     
     
         63 . The method of  claim 55  in which the annealing is done in a reducing atmosphere that contains hydrogen. 
     
     
         64 . The method of  claim 55  in which the annealing is done in carbon dioxide. 
     
     
         65 . The method of  claim 55  in which the annealing is done in vacuum. 
     
     
         66 . The method of  claim 55  in which the annealing is done in nitrogen saturated with water vapor. 
     
     
         67 . (canceled) 
     
     
         68 . The method of  claim 66  in which adhesion of the film to the substrate is promoted by creating at least one monolayer of a native oxide on the substrate. 
     
     
         69 . The method of  claim 68  in which the method is O 2  plasma ashing, reactive ion etch with O 2 , UV ozone treatment, applying a layer of SiO 2 , or cleaning in an oxidizing chemical solution. 
     
     
         70 . The method of  claim 69  in which the oxidizing chemical solution is sulfuric acid or and/or hydrogen peroxide. 
     
     
         71 . A nanoporous organic-containing oxide with a glassy wall structure and generally open pores, comprising:
 a metal or metalloid oxide in which the metal or metalloid oxide is partially replaced with an alkyl or aryl group, and   an amphiphilic block copolymer template that can be removed by the action of heat.   
     
     
         72 . The nanoporous organic-containing oxide material of  claim 71 , wherein the metalloid is silicon. 
     
     
         73 . The nanoporous organic-containing oxide of  claim 71 , wherein the material is spun into a film less than 2 μm thick upon anneal, and the material has a relationship between Young's modulus (E) and dielectric constant (k) bounded by the points-E=2.5 GPa, k=1.29 and E=8 GPa, k=2.6.