Polishing liquid and polishing method
A polishing liquid containing: abrasive grains containing a hydroxide of a tetravalent metal element; a monovalent acid component having no carboxy group; and a non-ionic polymer, in which a pH is 4.5 or less. A polishing method including a step of polishing a surface to be polished by using this polishing liquid.
1 . A polishing liquid comprising: abrasive grains containing a hydroxide of a tetravalent metal element; a monovalent acid component having no carboxy group;
and a non-ionic polymer, wherein
a mass ratio of a content of the acid component to a content of the hydroxide of the tetravalent metal element is 0.3 or more and 5 or less,
the non-ionic polymer contains a glycerin-based polymer and a polyoxyalkylene compound other than a glycerin-based polymer,
a mass ratio of a content of the glycerin-based polymer to a content of the polyoxyalkylene compound other than a glycerin-based polymer is 10 or more and 100 or less, and
a pH is 4.5 or less.
2 . The polishing liquid according to claim 1 , wherein a pKa of the acid component is 4.50 or less.
3 . The polishing liquid according to claim 1 , wherein the acid component contains a sulfonic acid compound.
4 . The polishing liquid according to claim 1 , further comprising a base component.
5 . The polishing liquid according to claim 4 , wherein the base component contains a pyrazole compound.
6 . The polishing liquid according to claim 1 , wherein the abrasive grains contain cerium hydroxide.
7 . The polishing liquid according to claim 1 , wherein the pH is 3.5 or more.
8 . The polishing liquid according to claim 1 , wherein the polishing liquid is used in polishing of a surface to be polished containing silicon oxide and silicon nitride.
9 . A polishing method comprising a step of polishing a surface to be polished by using the polishing liquid according to claim 1 .
10 . The polishing method according to claim 9 , wherein the surface to be polished contains silicon oxide and silicon nitride.
11 . The polishing liquid according to claim 1 , wherein the acid component contains an aminosulfonic acid compound.
12 . The polishing liquid according to claim 11 , wherein the aminosulfonic acid compound contains at least one selected from the group consisting of aromatic aminosulfonic acid, aliphatic aminosulfonic acid, sulfamic acid, and salts of these.
13 . The polishing liquid according to claim 1 , wherein the acid component contains at least one selected from the group consisting of sulfanilic acid, metanilic acid, sulfamic acid, and salts of these.
14 . The polishing liquid according to claim 1 , wherein the content of the acid component is 0.001 to 1% by mass on the basis of the total mass of the polishing liquid.
15 . The polishing liquid according to claim 1 , comprising no acid component containing a carboxy group.
16 . The polishing liquid according to claim 4 , wherein the base component contains a heterocyclic amine.
17 . The polishing liquid according to claim 1 , wherein the pH is 3.8 or less.