Polishing composition, production method of polishing composition, polishing method, and manufacturing method of semiconductor substrate
A polishing composition capable of increasing a polishing selectivity ratio of SiOC to silicon nitride, a production method of the polishing composition, a polishing method, and a manufacturing method of a semiconductor substrate are provided. The polishing composition contains abrasives having a zeta potential of −5 mV or less, a cationic surfactant, a phosphonic acid-based chelating agent, and a cationic compound having a molecular weight of 300 or less.
1 . A polishing composition comprising:
abrasives having a zeta potential of −5 mV or less;
a cationic surfactant;
a phosphonic acid-based chelating agent; and
a cationic compound having a molecular weight of 300 or less.
2 . The polishing composition according to claim 1 , wherein the polishing composition contains the cationic compound as a selectivity improver for improving a polishing selectivity ratio of SiOC to silicon nitride.
3 . The polishing composition according to claim 1 , wherein a content of the cationic compound is 0.01 g/L or more and 5 g/L or less.
4 . The polishing composition according to claim 1 , wherein the cationic compound includes an amine.
5 . The polishing composition according to claim 1 , wherein the cationic compound includes a quaternary ammonium cation.
6 . The polishing composition according to claim 1 , wherein the cationic compound includes tetrabutylammonium hydroxide (TBAH) or tetraethylammonium hydroxide (TEAH).
7 . The polishing composition according to claim 1 , wherein a zeta potential of the abrasives is −5 mV or less and −20 mV or more.
8 . The polishing composition according to claim 1 , wherein the cationic surfactant includes an amine oxide.
9 . The polishing composition according to claim 1 , wherein the cationic surfactant includes a dimethylamine oxide.
10 . The polishing composition according to claim 1 , wherein the cationic surfactant includes a decyl dimethylamine oxide.
11 . The polishing composition according to claim 1 , wherein the phosphonic acid-based chelating agent includes ethylenediamine tetramethylenephosphonic acid (EDTMP).
12 . The polishing composition according to claim 1 , wherein a pH is 6 or less.
13 . The polishing composition according to claim 1 , wherein the abrasives include anion-modified silica.
14 . The polishing composition according to claim 13 , wherein the silica is silica having a surface on which an organic acid is immobilized.
15 . The polishing composition according to claim 13 , wherein the silica is colloidal silica.
16 . The polishing composition according to claim 1 , wherein the polishing composition is used for an application of polishing a SiOC-containing object to be polished.
17 . A production method of the polishing composition according to claim 1 , the production method comprising:
mixing abrasives having a zeta potential of −5 mV or less, a cationic surfactant, a phosphonic acid-based chelating agent, a cationic compound having a molecular weight of 300 or less, and a liquid medium.
18 . A polishing method comprising:
polishing a SiOC-containing object to be polished by using the polishing composition according to claim 1 .
19 . A manufacturing method of a semiconductor substrate, the manufacturing method comprising:
polishing SiOC formed into a film on a semiconductor substrate by using the polishing composition according to claim 1 .
20 . The polishing composition according to claim 2 , wherein a content of the cationic compound is 0.01 g/L or more and 5 g/L or less.