Free radical-forming activator attached to solid and used to enhance CMP formulations

Abstract

The present invention provides a composition for chemical-mechanical polishing which comprises at least one abrasive particle having a surface at least partially coated by a activator. The activator comprises a metal other than a metal of Group 4(b), Group 5(b) or Group 6(b). The composition further comprises at least one oxidizing agent. The composition is believed to be effective by virtue of the interaction between the activator coated on the surface of the abrasive particles and the oxidizing agent, at the activator surface, to form free radicals. The invention further provides a method that employs the composition in the polishing of a feature or layer, such as a metal film, on a substrate surface. The invention additionally provides a substrate produced this method.

1 .- 74 . (canceled) 
   
   
       75 . A composition for chemical-mechanical polishing comprising:
 an aqueous fluid comprising at least one per-compound oxidizer that produces at least one oxygen-containing free radical when contacted with at least one activator; and   a plurality of metal oxide abrasive particles,   wherein the at least one activator comprises a photo-activated activator.   
   
   
       76 . The composition of claim  1 , wherein the photo-activated activator is selected from TiO 2 , Ti 2 O 3 , and oxides of Ta, W, V, Nb and combinations thereof. 
   
   
       77 . The composition of claim  1 , wherein the photo-activated activator is present in a matrix and the aqueous fluid contacts the matrix before passing between a pad and a substrate. 
   
   
       78 . The composition of claim  1 , wherein the amount of the least one activator is present in an amount from about 0.0001% to about 60% by weight. 
   
   
       79 . The composition of claim  1 , further comprising between 0.001 to about 1 weight percent of a stabilizer selected from vitamin B, vitamin C, citric acid, and mixtures thereof. 
   
   
       80 . The composition of claim  1 , wherein the at least one per-compound oxidizer comprises at least one peroxide. 
   
   
       81 . The composition of claim  1 , wherein the at least one per-compound oxidizer comprises hydrogen peroxide. 
   
   
       82 . The composition of claim  1 , wherein the metal oxide abrasive particles comprise alumina, silica, ceria and titania. 
   
   
       83 . The composition of claim  1 , wherein the metal oxide abrasive particles comprise alumina-coated silica. 
   
   
       84 . The composition of claim  1 , wherein the metal oxide abrasive particles have an effective diameter of about 30 to about 170 nanometers. 
   
   
       85 . The composition of claim  1 , wherein the metal oxide abrasive particles having an average particle size between 1 and 100 nanometers have a particle size distribution such that one sigma is 10% of the average particle size. 
   
   
       86 . The composition of claim  1 , further comprising between 0.001% to about 0.2% by weight of surfactant. 
   
   
       87 . The composition of claim  1 , further comprising a stabilization agent comprising ligands that bind with the at least one activator and reduce activator efficacy and that also reduce undesirable reactions that degrade the at least one per-compound oxidizer. 
   
   
       88 . The composition of claim  1 , further comprising between 0.001% and 2% by weight of a stabilization agent comprising ligands that bind with the at least one activator and reduce activator efficacy and that also stabilize the at least one per-compound oxidizer. 
   
   
       89 . A method of chemically mechanically polishing comprising:
 (A) providing a semiconductor wafer substrate having a surface to be polished comprising tungsten and a dielectric material;   (B) providing an aqueous composition comprising: 1) at least one per-compound oxidizer that produces at least one oxygen-containing free radicals when contacted with at least one activator; and   a plurality of metal oxide abrasive particles,   wherein said at the least one activator comprises a photo-activated activator, and   (C) contacting the substrate surface with an abrasive and with the aqueous composition thereby polishing tungsten from the surface of the semiconductor wafer substrate.   
   
   
       90 . The method of claim  16 , wherein the photo-activated activator is selected from TiO 2 , Ti 2 O 3 , and oxides of Ta, W, V, Nb and combinations thereof. 
   
   
       91 . The composition of claim  16 , wherein the photo-activated activator is present in a matrix and the aqueous fluid contacts the matrix before passing between a pad and a substrate.