Method for polishing silicon substrate and polishing composition set
Provided are a method for polishing a silicon substrate according to which PID can be reduced and a polishing composition set usable in the polishing method. The silicon substrate polishing method provided by this invention comprises a stock polishing step and a final polishing step. The stock polishing step comprises several stock polishing sub-steps carried out on one same platen. The several stock polishing sub-steps comprise a final stock polishing sub-step carried out while supplying a final stock polishing slurry P F to the silicon substrate. The total amount of the final stock polishing slurry P F supplied to the silicon substrate during the final stock polishing sub-step has a total weight of Cu and a total weight of Ni, at least one of which being 1 μg or less.
1. A method for polishing a silicon substrate, the method comprising
a stock polishing step and a final polishing step, wherein:
the stock polishing step comprises several stock polishing sub-steps that are carried out on one same platen;
the several stock polishing sub-steps comprise a final stock polishing sub-step that is carried out while supplying a final stock polishing slurry P F to the silicon substrate;
the total amount of the final stock polishing slurry P F supplied to the silicon substrate during the final stock polishing sub-step has a total weight of Cu and a total weight of Ni, at least one of which being 1 μg or less;
the several stock polishing sub-steps are carried out wherein a time for each stock polishing sub-step is reduced to a time shorter than its preceding step; and
both sides of the silicon substrate are polished simultaneously in each of the several stock polishing sub-steps and one side of the silicon substrate is polished in the final polishing step.
2. The polishing method according to claim 1 , wherein, in the final stock polishing sub-step, the total weight of Cu and the total weight of Ni in the total amount of the final stock polishing slurry P F supplied to the silicon substrate add to a total of 2 μg or less.
3. A method for polishing a silicon substrate, the method comprising a stock polishing step and a final polishing step, wherein:
the stock polishing step comprises several stock polishing sub-steps that are carried out on one same platen;
the several stock polishing sub-steps comprise:
a final stock polishing sub-step that is carried out while supplying a final stock polishing slurry P F to the silicon substrate; and
a non-final stock polishing sub-step that is carried out before the final stock polishing sub-step while supplying a non-final stock polishing slurry P N having a higher concentration of at least Cu or Ni than the concentration of the same element in the final stock polishing slurry P F ;
the several stock polishing sub-steps are carried out wherein a time for each stock polishing sub-step is reduced to a time shorter than its preceding step;
both sides of the silicon substrate are polished simultaneously in each of the several stock polishing sub-steps and one side of the silicon substrate is polished in the final polishing step.
4. The polishing method according to claim 3 , wherein the non-final stock polishing slurry P N has a weight of at least Cu or Ni per 10 g of abrasive contained therein greater than the weight of the same element per 10 g of abrasive contained in the final stock polishing slurry P F .
5. The polishing method according to claim 3 , wherein the final stock polishing slurry P F has a weight of at least Cu or Ni of 0.02 μg or less per 10 g of abrasive contained in the final stock polishing slurry P F .
6. The polishing method according to claim 3 , wherein the final stock polishing slurry P F has a combined weight of Cu and Ni of 0.1 μg or less per 10 g of abrasive contained in the final stock polishing slurry P F .
7. The polishing method according to claim 3 , wherein the non-final stock polishing slurry P N has a combined weight of Cu and Ni per 10 g of abrasive contained therein greater than the combined weight of Cu and Ni per 10 g of the abrasive contained in the final stock polishing slurry P F .
8. The polishing method according to claim 3 , wherein the stock polishing step is carried out on a silicon substrate provided with a hard laser mark.
9. A method for polishing a silicon substrate, the method comprising
a stock polishing step and a final polishing step, wherein:
the stock polishing step comprises several stock polishing sub-steps that are carried out on one same platen;
the several stock polishing sub-steps comprise:
a final stock polishing sub-step that is carried out while supplying a final stock polishing slurry P F to the silicon substrate; and
a non-final stock polishing sub-step that is carried out before the final stock polishing sub-step while supplying a non-final stock polishing slurry P N having a higher concentration of at least Cu or Ni than the concentration of the same element in the final stock polishing slurry P F ; and
both sides of the silicon substrate are polished simultaneously in each of the several stock polishing sub-steps and one side of the silicon substrate is polished in the final polishing step.