Polishing agent and method for polishing substrate using the polishing agent

Abstract

Disclosed is a polishing agent comprising: water; tetravalent metal hydroxide particles; and an additive, wherein the additive contains at least one of a cationic polymer and a cationic polysaccharide. The present invention can provide a polishing agent which is capable of polishing an insulating film at a high speed with less polishing flaws, and having a high polishing rate ratio of a silicon oxide film and a stopper film, in the CMP technology of flattening insulating film. The present invention can also provide a polishing agent set for storing the polishing agent, and a method for polishing a substrate using this polishing agent.

1 - 13 . (canceled) 
     
     
         14 . A polishing agent comprising: water, tetravalent metal hydroxide particles, and an additive, wherein
 the additive comprises at least one selected from the group consisting of an amino sugar and a polysaccharide having an amino sugar, and at least one selected from the group consisting of a second additive and a water-soluble polymer,   when the additive comprises a chitosan, the chitosan has the degree of deacetylation of 20% or greater,   when the additive comprises a chitosan derivative, the chitosan derivative comprises at least one selected from the group consisting of chitosan pyrrolidone carboxylic acid salt, cationized chitosan, hydroxypropyl chitosan, chitosan lactate, glycerylated chitosan, glycol chitosan, carboxymethylchitosan, and carboxymethylchitosan succinamide,   the second additive comprises at least one selected from the group consisting of a carboxylic acid, an amino acid, an amphoteric surfactant, an anionic surfactant, a nonionic surfactant, and a cationic surfactant,   the water-soluble polymer comprises at least one selected from the group consisting of alginic acid, pectinic acid, carboxymethyl cellulose, agar, cardlan, pullulan, a polycarboxylic acid and salt thereof, a vinyl polymer, an acrylic polymer, polyethylene glycol, polyoxypropylene, polyoxyethylene-polyoxypropylene condensate, and a polyoxyethylene-polyoxypropylene block polymer of ethylenediamine.   
     
     
         15 . The polishing agent according to  claim 14 , wherein the total amount of the amino sugar and the polysaccharide having an amino sugar is 0.0001 parts by weight or more relative to 100 parts by weight of the polishing agent. 
     
     
         16 . The polishing agent according to  claim 14 , wherein the amount of the second additive is from 0.01 parts by weight to 10 parts by weight, relative to 100 parts of the polishing agent. 
     
     
         17 . The polishing agent according to  claim 14 , wherein the amount of the water-soluble polymer is from 0.01 parts by weight to 5 parts by weight, relative to 100 parts of the polishing agent. 
     
     
         18 . The polishing agent according to  claim 14 , wherein the additive comprises at least one selected from the group consisting of the chitosan and the chitosan derivative. 
     
     
         19 . The polishing agent according to  claim 14 , wherein the second additive comprises the carboxylic acid. 
     
     
         20 . The polishing agent according to  claim 14 , wherein the second additive comprises at least one selected from the group consisting of formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, and lactic acid. 
     
     
         21 . The polishing agent according to  claim 14 , wherein the water-soluble polymer comprises the vinyl polymer. 
     
     
         22 . The polishing agent according to  claim 14 , wherein the water-soluble polymer comprises at least one selected from the group consisting of polyvinyl alcohol, polyvinylpyrrolidone, and polyacrolein. 
     
     
         23 . The polishing agent according to  claim 14 , wherein the pH of the polishing agent is from 3.0 to 7.0. 
     
     
         24 . The polishing agent according to  claim 14 , wherein the average particle size of the tetravalent metal hydroxide particles is from 1 nm to 400 nm. 
     
     
         25 . The polishing agent according to  claim 14 , wherein the zeta potential of the tetravalent metal hydroxide particles in the polishing agent is +10 mV or higher. 
     
     
         26 . The polishing agent according to  claim 14 , wherein the tetravalent metal hydroxide comprises at least one of selected from the group consisting of rare earth metal hydroxides and zirconium hydroxide. 
     
     
         27 . The polishing agent according to  claim 26 , wherein the rare earth metal hydroxides comprise cerium hydroxide. 
     
     
         27 . The polishing agent according to  claim 14 , wherein the specific surface area of the tetravalent metal hydroxide particles is 100 m 2 /g or higher. 
     
     
         28 . The polishing agent according to  claim 14 , wherein the amount of the tetravalent metal hydroxide particles is from 0.001 parts by weight to 5 parts by weight relative to 100 parts by weight of the polishing agent. 
     
     
         29 . The polishing agent according to  claim 14 , wherein the water-soluble polymer comprises polyvinyl alcohol. 
     
     
         30 . A method of polishing a substrate, the method comprising the steps of:
 applying pressure on a substrate on which a film to be polished is formed by pressing the substrate against a polishing cloth of a polishing platen; and   moving the substrate and the polishing platen relatively to each other to polish the film to be polished while supplying the polishing agent according to  claim 14  between the film to be polished and the polishing cloth.   
     
     
         31 . The method of polishing according to  claim 30 , wherein the Shore D hardness of the polishing cloth is 70 or harder. 
     
     
         32 . A polishing agent set comprising a slurry and an additive liquid, which are stored separately and mixed immediately before polishing or at the time of polishing to be the polishing agent according to  claim 14 ,
 wherein the slurry contains the tetravalent metal hydroxide particles and the water, and the additive liquid contains the additive and the water.