Silica-based organic film and method of manufacturing the same, and base material comprising organic film

Abstract

A film is provided which can be applied to high-temperature processes and can fill microspaces between wirings without forming voids and prevent the occurrence of side etching, and also causes less degassing due to increase of an atmospheric temperature. A coating solution containing a reaction product which is obtained by hydrolyzing at least one first alkoxysilane compound selected from the group consisting of compounds represented by general formula (I) and compounds represented by general formula (II) in an organic solvent in the presence of an acid catalyst is applied on a target material to form a coating film, and then the coating film is baked in an atmosphere having an oxygen concentration of 1000 ppm or less to form a silica-based organic film. At least one second alkoxysilane compound selected from the group consisting of compounds represented by general formula (III) may be used in combination: R 1 2 Si(OR 2 ) 2   (I) R 3 Si(OR 4 ) 3   (II) Si(OR 5 ) 4   (III) wherein R 1 and R 3 each represents an alkyl group having 1 to 4 carbon atoms or a phenyl group, R 2 , R 4 , and R 5 each represents an alkyl group having 1 to 4 carbon atoms.

What is claimed is:  
     
         1 . A method of manufacturing a silica-based organic film, comprising the steps of: 
 applying a coating solution on a target material to form a coating film, the coating solution containing a reaction product obtained by hydrolyzing, in an organic solvent in the presence of an acid catalyst, at least one first alkoxysilane compound selected from the group consisting of compounds represented by general formula (I):   R 1   2 Si(OR 2 ) 2   (I)   wherein R 1  represents an alkyl group having 1 to 4 carbon atoms or a phenyl group, and    R 2  represents an alkyl group having 1 to 4 carbon atoms,    and compounds represented by general formula (II):   R 3 Si(OR 4 ) 3   (II)   wherein R 3  represents an alkyl group having 1 to 4 carbon atoms or a phenyl group, and    R 4  represents an alkyl group having 1 to 4 carbon atoms, and    baking the coating film in an atmosphere having an oxygen concentration of 1000 ppm or less to form a film.    
     
     
         2 . A method of manufacturing a silica-based organic film, comprising the steps of: 
 applying a coating solution on a target material to form a coating film, the coating solution containing a reaction product obtained by hydrolyzing, in an organic solvent in the presence of an acid catalyst, at least one said first alkoxysilane compound and at least one second alkoxysilane compound selected from the group consisting of compounds represented by general formula (III):   Si(OR 5 ) 4   (III)   wherein R 5  represents an alkyl group having 1 to 4 carbon atoms, and    baking the coating film in an atmosphere having an oxygen concentration of 1000 ppm or less to form a film.    
     
     
         3 . The method of manufacturing a silica-based organic film according to  claim 2 , wherein a molar ratio of the first alkoxysilane compound to the second alkoxysilane compound is from 1:2 to 4:1.  
     
     
         4 . The method of manufacturing a silica-based organic film according to  claim 1  or  2 , wherein a carbon content in the film is from 6 to 18 atm %.  
     
     
         5 . The method of manufacturing a silica-based organic film according to  claim 1  or  2 , wherein an organic group content, which is represented as a ratio of the total of a peak area of SiR 1  and a peak area of SiR 3  to a peak area of Si—O—Si in a spectrum obtained by measuring an infrared absorption spectrum of the film, is 0.01 or more.  
     
     
         6 . The method of manufacturing a silica-based organic film according to  claim 1  or  2 , wherein an etching rate of the film in wet etching using hydrofluoric acid having a concentration of 0.5% by weight is 60 angstroms/min or less.  
     
     
         7 . The method of manufacturing a silica-based organic film according to  claim 1  or  2 , wherein a baking temperature in the baking step is from 600° C. to 750° C.  
     
     
         8 . The method of manufacturing a silica-based organic film according to  claim 1 , wherein the hydrolysis treatment is conducted by adding water in an amount of 2 to 10 mol per 1 mol of the first alkoxysilane compound.  
     
     
         9 . The method of manufacturing a silica-based organic film according to  claim 2 , wherein the hydrolysis treatment is conducted by adding water in an amount of 2 to 10 mol per 1 mol of the total amount of the first alkoxysilane compound and the second alkoxysilane compound.  
     
     
         10 . The method of manufacturing a silica-based organic film according to  claim 1  or  2 , wherein the reaction product is a siloxane oligomer.  
     
     
         11 . The method of manufacturing a silica-based organic film according to  claim 10 , wherein a weight-average molecular weight of the siloxane oligomer is within a range from 1000 to 4000.  
     
     
         12 . The method of manufacturing a silica-based organic film according to  claim 1  or  2 . wherein R 1  and R 3  are methyl groups.  
     
     
         13 . The method of manufacturing a silica-based organic film according to  claim 1  or  2 , wherein the water content with respect to the amount of the solvent excluding the solid content of the coating solution is from 1 to 30% by weight.  
     
     
         14 . The method of manufacturing a silica-based organic film according to  claim 1  or  2 , wherein the baking step is conducted in an inert gas atmosphere.  
     
     
         15 . The method of manufacturing a silica-based organic film according to  claim 14 , wherein the inert gas is a nitrogen gas.  
     
     
         16 . The method of manufacturing a silica-based organic film according to  claim 1  or  2 , further comprising a first drying step of heating the film to 50 to 100° C. for 30 to 90 seconds between the applying step and the baking step, a second drying step of heating to 130 to 170° C. for 30 to 90 seconds after the first drying step, and a third drying step of heating to 190 to 220° C. for 30 to 90 seconds after the second drying step.  
     
     
         17 . A silica-based organic film obtained by the method of  claim 1  or  2 .  
     
     
         18 . A silica-based organic film containing polyorganosiloxane, wherein an etching rate of the film in wet etching using hydrofluoric acid having a concentration of 0.5% by weight is 60 angstroms/min or less.  
     
     
         19 . The silica-based organic film according to  claim 18 , wherein an organic group content, which is represented as a ratio of the total of a peak area of SiR 1  and a peak area of SiR 3  to a peak area of Si—O—Si in a spectrum obtained by measuring an infrared absorption spectrum of the film, is 0.01 or more.  
     
     
         20 . The silica-based organic film according to  claim 18 , wherein a carbon content is from 6 to 18 atm %.  
     
     
         21 . A base material comprising a substrate and a first wiring pattern which is heat-resistant to a temperature of 600° C. or higher provided on the substrate, said base material further comprising the silica-based organic film of  claim 17  which covers the first wiring pattern.  
     
     
         22 . The base material according to  claim 21 , wherein the first wiring pattern contains a polycrystalline silicon.  
     
     
         23 . The base material according to  claim 21 , further comprising an intermediate layer formed by a chemical vapor phase process between the first wiring pattern and the silica-based organic film.  
     
     
         24 . The base material according to  claim 23 , wherein a minimum value of a wiring distance of the first wiring pattern in the state of being coated with the intermediate layer is 0.25 μm or less.  
     
     
         25 . The base material according to  claim 23 , wherein the intermediate layer contains silicon nitride.  
     
     
         26 . The base material according to  claim 23 , which is provided with contact holes piercing through the silica-based organic film and the intermediate layer, said contact holes being filled with a conductive material.  
     
     
         27 . The base material according to  claim 26 , wherein the conductive material contains tungsten.  
     
     
         28 . The base material according to  claim 21 , wherein a second wiring pattern which is heat-resistant to a temperature of  400  to 500° C. is provided on the opposite side of the substrate relative to the silica-based organic film.  
     
     
         29 . The base material according to  claim 28 , wherein the second wiring pattern contains aluminum.