Method for producing polished object and polishing composition kit
[Problem] To provide a method for producing a polished object, which can remarkably reduce a haze level on a surface of the object to be polished while defects are significantly reduced. [Solution] A method for producing a polished object, which includes a double-side polishing step in which an object to be polished is subjected to double-side polishing using a double-side polishing composition including first abrasive grains having an average primary particle diameter of 40 nm or more and a nitrogen-containing water-soluble polymer to obtain a double-side polished object; and a single-side polishing step in which the double-side polished object is subjected to single-side polishing using a single-side polishing composition including second abrasive grains having an average primary particle diameter of 40 nm or less and a water-soluble polymer, and in which a ratio of an average primary particle diameter (A) of the first abrasive grains with respect to an average primary particle diameter (B) of the second abrasive grains (A)/(B) is more than 1 and 2.5 or less.
1. A method for producing a polished object, comprising:
a double-side polishing step in which an object to be polished is subjected to double-side polishing using a double-side polishing composition including first abrasive grains having an average primary particle diameter of 40 nm or more and a nitrogen-containing water-soluble polymer to obtain a double-side polished object; and
a single-side polishing step in which the double-side polished object is subjected to single-side polishing using a single-side polishing composition including second abrasive grains having an average primary particle diameter of 40 nm or less and a water-soluble polymer, wherein
a ratio of an average primary particle diameter (A) of the first abrasive grains with respect to an average primary particle diameter (B) of the second abrasive grains (A)/(B) is more than 1 and 2.5 or less, and
wherein the concentration of the water-soluble polymer in the single-side polishing composition is 5 times higher than that of the nitrogen-containing water-soluble polymer in the double-side polishing composition.
2. The method for producing a polished object according to claim 1 , wherein (A)/(B) is 1.6 or more and less than 2.3.
3. The method for producing a polished object according to claim 1 , wherein the nitrogen-containing water-soluble polymer has one or more nitrogen atoms in a monomer unit, or one or more nitrogen atoms in a part of side chain.
4. The method for producing a polished object according to claim 1 , wherein the nitrogen-containing water-soluble polymer is selected from the group consisting of polyvinyl imidazole, polyvinyl carbazole, polyvinyl pyrrolidone, poly N-vinylformamide, polyvinyl caprolactam, and polyvinyl piperidine.
5. The method for producing a polished object according to claim 1 , wherein
the single-side polishing step is performed multiple times, and
a water-soluble polymer used in the last single-side polishing step includes at least one selected from a polymer containing an oxyalkylene unit, a nitrogen-containing water-soluble polymer, polyvinyl alcohol, and a cellulose derivative.
6. The method for producing a polished object according to claim 1 , wherein the object to be polished is a semiconductor wafer.
7. The method for producing a polished object according to claim 6 , wherein the semiconductor is silicon.
8. A polishing composition kit comprising:
first abrasive grains having an average primary particle diameter of 40 nm or more, used in double-side polishing; a nitrogen-containing water-soluble polymer used in double-side polishing;
second abrasive grains having an average primary particle diameter of 40 nm or less, used in single-side polishing; and a water-soluble polymer used in single-side polishing, wherein
a ratio of an average primary particle diameter (A) of the first abrasive grains with respect to an average primary particle diameter (B) of the second abrasive grains (A)/(B) is more than 1 and 2.5 or less, and
wherein the concentration of the water-soluble polymer in the single-side polishing composition is 5 times higher than that of the nitrogen-containing water-soluble polymer in the double-side polishing composition.
9. A double-side polishing composition used in the method for producing a polished object according to claim 1 ,
wherein the double-side polishing composition comprises abrasive grains having an average primary particle diameter of 40 nm or more and a nitrogen-containing water-soluble polymer.
10. A single-side polishing composition used in the method for producing a polished object according to claim 1 ,
wherein the single-side polishing composition comprises abrasive grains having an average primary particle diameter of 40 nm or less and a water-soluble polymer.