Method of preparing metal oxide suspension
Disclosed herein is a method of preparing a metal oxide suspension, which is advantageous due to the prevention of hydration and agglomeration of the metal oxide and a simple preparation process. The method of preparing a metal oxide suspension according to this invention includes preparing metal oxide, mixing the metal oxide with a solvent and a surface treating agent to obtain a mixture, and wet milling the mixture such that the metal oxide of the mixture has a nanoscale particle size and the metal oxide is uniformly dispersed in the mixture.
1 . A method of preparing a metal oxide suspension, the method comprising:
preparing a metal oxide;
mixing the metal oxide with a solvent and a surface treating agent to obtain a mixture; and
wet milling the mixture such that the metal oxide of the mixture has a nanoscale particle size and the metal oxide is uniformly dispersed in the mixture.
2 . The method of claim 1 , wherein the mixing and wet milling are performed sequentially or simultaneously.
3 . The method of claim 1 , wherein the phase variation of the metal oxide having a nanoscale particle size, which is induced by hydration, does not occur during the wet milling.
4 . The method of claim 1 , wherein the surface treating agent comprises an organic acid having at least one carboxyl group.
5 . The method of claim 1 , wherein the surface treating agent comprises an oligomeric anionic surfactant having at least one functional group selected from the group consisting of a sulfonic acid, a sulfonate, a phosphonic acid, a phosphonate, and a phosphate.
6 . The method of claim 1 , wherein the surface treating agent comprises a cationic surfactant or a non-ionic surfactant.
7 . The method of claim 1 , wherein the surface treating agent comprises a polymer or a salt thereof having at least one functional group selected from the group consisting of a carboxylic acid, a carboxylate, a sulfonate, a phosphonic acid, a phosphonate, a phosphate, and an ethylene oxide.
8 . The method of claim 1 , wherein the surface treating agent comprises a copolymer obtained by polycondensing at least one monomer having a carboxylic acid, a carboxylate, a sulfonate a phosphonic acid, a phosphonate, or a phosphate, and at least one monomer having at least one amide selected from the group consisting of formamide, dimethylformamide, acetamide, benzamide, and acrylamide.
9 . The method of claim 1 , wherein the metal oxide comprises at least one selected from the group consisting of alumina, magnesia, zirconia, seria, titania, zinc oxide, tungsten oxide, and mixtures thereof.
10 . The method of claim 1 , wherein the metal oxide is γ-, θ-, κ-, δ-, or τ-alumina.
11 . The method of claim 1 , wherein the metal oxide milled by the wet milling has a particle size of 10˜300 nm.
12 . The method of claim 1 , wherein the mixing includes adding an oxidant, a complexing agent, an antioxidant, and/or a pH controlling agent to the mixture.
13 . The method of claim 1 , further comprising adding an oxidant, a complexing agent, an antioxidant, and/or a pH controlling agent after the wet milling.
14 . The method of claim 12 or 13 , wherein the metal oxide suspension is used for chemical mechanical polishing of metal wires.
15 . The method of claim 1 , wherein the wet milling is performed using beads having a size of 0.01˜2.0 mm.