Plasma curing process for porous silica thin film

Abstract

Low dielectric constant films with improved elastic modulus. An SiO 2 -containing plasma cured coating having a first dielectric constant and having a first elastic modulus is provided, the coating being formed by providing a porous network coating produced from a resin molecule containing at least 2 Si—H groups, and plasma curing the porous network coating to reduce an amount of Si—H bonds. Plasma curing of the network coating yields a coating with improved modulus, but with a higher dielectric constant. Accordingly, an SiO 2 -containing plasma cured coating is also provided, the coating being formed by annealing the plasma cured coating to produce an annealed, plasma cured coating having a second dielectric constant which is less than the first dielectric constant and having a second elastic modulus which is comparable to the first elastic modulus. The annealed, SiO 2 -containing plasma cured coating can have a dielectric constant between about 1.1 and about 3.5 and an elastic modulus greater than or about 4 GPa. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR §1.72(b).

What is claimed is:  
     
         1 . An SiO 2 -containing plasma cured coating having a first dielectric constant and having a first elastic modulus, the coating being formed by 
 providing a porous network coating produced from a resin molecule containing at least 2 Si—H groups; and    plasma curing the porous network coating to reduce an amount of Si—H bonds.    
     
     
         2 . The SiO 2 -containing plasma cured coating of  claim 1  being formed by plasma curing the porous network coating for between about 15 and about 120 seconds.  
     
     
         3 . The SiO 2 -containing plasma cured coating of  claim 1  being formed by plasma curing the porous network coating at a temperature less than or about 350° C.  
     
     
         4 . The SiO 2 -containing plasma cured coating of  claim 1  being formed by plasma curing the porous network coating at a temperature between about 80 and about 280° C.  
     
     
         5 . The SiO 2 -containing plasma cured coating of  claim 1  being formed by plasma curing the porous network coating at a temperature between about 195 and about 230° C.  
     
     
         6 . The SiO 2 -containing plasma cured coating of  claim 1  being formed by annealing the plasma cured coating to produce an annealed, plasma cured coating having a second dielectric constant which is less than the first dielectric constant and having a second elastic modulus which is comparable to the first elastic modulus.  
     
     
         7 . The SiO 2 -containing plasma cured coating of  claim 6  being formed by annealing the plasma cured coating at a temperature less than or about 475° C.  
     
     
         8 . The SiO 2 -containing plasma cured coating of  claim 6  being formed by annealing the plasma cured coating at a temperature between about 350 and about 450° C.  
     
     
         9 . The SiO 2 -containing plasma cured coating of  claim 6  being formed by annealing the plasma cured coating for no more than or about 180 seconds.  
     
     
         10 . The SiO 2 -containing plasma cured coating of  claim 6  wherein the second elastic modulus of the annealed, plasma cured coating is greater than or about 4 GPa.  
     
     
         11 . The SiO 2 -containing plasma cured coating of  claim 6  wherein the second elastic modulus of the annealed, plasma cured coating is between about 4 and about 10 GPa.  
     
     
         12 . The SiO 2 -containing plasma cured coating of  claim 6  wherein the second dielectric constant of the annealed, plasma cured coating is between about 1.1 and about 3.5.  
     
     
         13 . The SiO 2 -containing plasma cured coating of  claim 6  wherein the second dielectric constant of the annealed, plasma cured coating is between about 2 and about 2.5.  
     
     
         14 . An annealed, SiO 2 -containing plasma cured coating having a dielectric constant between about 1.1 and about 3.5 and an elastic modulus greater than or about 4 GPa, the coating being formed by 
 providing a porous network coating produced from a resin molecule containing at least 2 Si—H groups;    plasma curing the porous network coating to reduce an amount of Si—H bonds and to produce a plasma cured coating; and    annealing the plasma cured coating.    
     
     
         15 . The annealed, SiO 2 -containing plasma cured coating of  claim 14  having an elastic modulus between about 4 and about 10 GPa.  
     
     
         16 . The annealed, SiO 2 -containing plasma cured coating of  claim 14  having a dielectric constant between about 2 and about 2.5.  
     
     
         17 . An electronic device containing a plasma cured coating, the coating being formed by 
 providing a porous network coating produced from a resin molecule containing at least 2 Si—H groups; and    plasma curing the porous network coating to reduce an amount of Si—H bonds.    
     
     
         18 . An electronic device containing an annealed, plasma cured coating, the coating being formed by 
 providing a porous network coating produced from a resin molecule containing at least 2 Si—H groups;    plasma curing the porous network coating to reduce an amount of Si—H bonds and to produce a plasma cured coating; and    annealing the plasma cured coating.    
     
     
         19 . An electronic circuit containing a plasma cured coating, the coating being formed by 
 providing a porous network coating produced from a resin molecule containing at least 2 Si—H groups; and    plasma curing the porous network coating to reduce an amount of Si—H bonds.    
     
     
         20 . An electronic circuit containing an annealed, plasma cured coating, the coating being formed by 
 providing a porous network coating produced from a resin molecule containing at least 2 Si—H groups;    plasma curing the porous network coating to reduce an amount of Si—H bonds and to produce a plasma cured coating; and    annealing the plasma cured coating.    
     
     
         21 . A substrate having a plasma cured coating, the coating being formed by 
 providing a porous network coating produced from a resin molecule containing at least 2 Si—H groups; and    plasma curing the porous network coating to reduce an amount of Si—H bonds.    
     
     
         22 . A substrate having an annealed, plasma cured coating, the coating being formed by 
 providing a porous network coating produced from a resin molecule containing at least 2 Si—H groups;    plasma curing the porous network coating to reduce an amount of Si—H bonds and to produce a plasma cured coating; and    annealing the plasma cured coating.    
     
     
         23 . A porous SiO 2 -containing plasma cured coating having a dielectric constant between about 1.1 and about 3.5 and an elastic modulus between about 4 and about 10 GPa.  
     
     
         24 . A porous SiO 2 -containing plasma cured coating having a dielectric constant between about 2 and about 2.9 and an elastic modulus between about 5.7 and about 9.1 GPa.  
     
     
         25 . A porous SiO 2 -containing plasma cured coating produced from a resin molecule containing at least 2 Si—H groups, the coating having a dielectric constant between about 1.1 and about 3.5 and an elastic modulus between about 4 and about 10 GPa.  
     
     
         26 . A porous SiO 2 -containing plasma cured coating produced from a resin molecule containing at least 2 Si—H groups, the coating having a dielectric constant between about 2 and about 2.9 and an elastic modulus between about 5.7 and about 9.1 GPa.  
     
     
         27 . The porous SiO 2 -containing plasma cured coating of  claim 25  wherein the resin molecule has the formula:  
       {R 3 SiO 1/2 } a {R 2 SiO 2/2 } b {RSiO 3/2 } c {SiO 4/2 } d    
       wherein each R is independently selected from the group consisting of hydrogen, alkyl, alkenyl, and aryl groups or alkyl, alkenyl, and aryl groups substituted with halogen, nitrogen, oxygen sulfur or silicon atoms, with the proviso that at least 2 R groups are hydrogen.  
     
     
         28 . The porous SiO 2 -containing plasma cured coating of  claim 25  wherein the resin molecule comprises a hydrogen silsesquioxane resin molecule of the structure selected from (HSiO 3/2 ) n , a polymer having units of the formula HSi(OH) a O 3-x/2  and a polymer having units of the formula HSi(OH) x (OR) y O z/2 , wherein each R is independently an organic group which, when bonded to silicon through the oxygen atom, forms a hydrolyzable substituent, a=0-2, x=0-2, y=0-2, z=1-3, x+y+z=3, n is an integer greater than 3 and the average value of y over all of the units of the polymer is greater than 0.