Polishing agent, stock solution for polishing agent, and polishing method
A polishing agent containing abrasive grains and water, in which the abrasive grains contain silica particles, an average particle diameter R ave of the abrasive grains is 50 nm or more, a ratio R ave /R min of the average particle diameter R ave to an average minor diameter R min of the abrasive grains is 1.0 to 2.0, and a zeta potential of the abrasive grains in the polishing agent is positive.
1. A polishing agent comprising:
abrasive grains, and
water,
wherein the abrasive grains contain silica particles,
an average secondary particle diameter R ave of the abrasive grains is 50 nm or more,
a ratio R ave /R min of the average secondary particle diameter R ave to an average minor diameter R min of the abrasive grains is 1.0 to 1.3, and
a zeta potential of the abrasive grains in the polishing agent is positive.
2. The polishing agent according to claim 1 , wherein the silica particles contain colloidal silica.
3. The polishing agent according to claim 1 , wherein the average secondary particle diameter R ave is 50 to 100 nm.
4. The polishing agent according to claim 1 , wherein the average secondary particle diameter R ave exceeds 60 nm.
5. The polishing agent according to claim 1 , wherein the ratio R ave /R min is 1.1 to 1.3.
6. The polishing agent according to claim 1 , further comprising a pH adjusting agent.
7. The polishing agent according to claim 1 , wherein a pH is 2.0 to 4.0.
8. A stock solution for a polishing agent for obtaining the polishing agent according to claim 1 ,
wherein the stock solution is diluted with water to obtain the polishing agent.
9. The polishing agent according to claim 1 , wherein the average secondary particle diameter R ave is more than 70 nm.
10. The polishing agent according to claim 1 , wherein the average secondary particle diameter R ave is 80 nm or more.
11. The polishing agent according to claim 1 , wherein the zeta potential of the abrasive grains is 20 mV or less.
12. The polishing agent according to claim 1 , wherein the average secondary particle diameter R ave and the ratio R ave /R min are values of all silica particles contained in the polishing agent.
13. A polishing method comprising a step of polishing and removing at least a part of a silicon oxide film by using the polishing agent according to claim 1 .
14. The polishing method according to claim 13 , wherein the silicon oxide film comprises at least one selected from the group consisting of a TEOS film and a SiH 4 film.
15. The polishing method according to claim 13 , wherein the silicon oxide film comprises a TEOS film.
16. The polishing method according to claim 13 , wherein the silicon oxide film comprises a SiH 4 film.
17. A polishing method comprising a step of polishing and removing at least a part of a silicon oxide film by using the polishing agent obtained by diluting the stock solution for a polishing agent according to claim 8 with water.
18. The polishing method according to claim 17 , wherein the silicon oxide film comprises at least one selected from the group consisting of a TEOS film and a SiH 4 film.
19. The polishing method according to claim 17 , wherein the silicon oxide film comprises a TEOS film.
20. The polishing method according to claim 17 , wherein the silicon oxide film comprises a SiH 4 film.
21. A polishing agent comprising:
abrasive grains, and
water,
wherein the abrasive grains contain silica particles,
an average secondary particle diameter R ave of the abrasive grains is 50 nm or more,
a ratio R ave /R min of the average secondary particle diameter R ave to an average minor diameter R min of the abrasive grains is 1.71 to 2.0, and
a zeta potential of the abrasive grains in the polishing agent is positive.
22. The polishing agent according to claim 21 , wherein the average secondary particle diameter R ave and the ratio R ave /R min are values of all silica particles contained in the polishing agent.