Preparation method of high purity cerium oxide powder, and CMP slurry containing the same

Abstract

The present invention relates to a method for preparing cerium oxide (CeO2) by forming high purity cerium nitrate hydrate (Ce(NO3)3·6H2O) which is an intermediate. More specifically, the method for preparing cerium oxide comprises: recovering precipitates by titrating sodium hydroxide in a cerium chloride composition and separating supernatants and precipitates; obtaining solid cerium precursors by finely spraying and filtering an excess of purified water, wherein the spraying and filtering process is performed to reduce praseodymium (Pr) contained in the precipitates; and obtaining cerium oxide using cerium nitrate hydrate formed by titrating nitric acids in the cerium precursors. In addition, the present invention provides high purity cerium oxide powder, a preparation method thereof, and CMP slurry containing the same. The cerium oxide is prepared using cerium nitrate hydrate as an intermediate, wherein the purity of the cerium nitrate hydrate is increased through purification by titrating sodium hydroxide and washing by finely spraying an excess of purified water, so the high purity cerium oxide powder contains virtually no impurities of various rare-earth elements, especially praseodymium which has an adverse effect on properties of CMP slurry.

Description

technical field [0001] The present invention relates to a method for producing cerium oxide by forming a highly purified intermediate cerium nitrate hydrate, in particular to a method for refining by sodium hydroxide titration and washing with a large amount of purified water through fine spraying, and using highly purified cerium nitrate hydrate as the It is made of intermediates, so it basically does not contain various rare earth element impurities, especially high-purity cerium oxide powder that does not contain praseodymium that has a serious adverse effect on the physical properties of CMP slurry, its preparation method and CMP slurry containing it. Background technique [0002] Cerium oxide powder is a high-performance ceramic (ceramic) powder used as a raw material for abrasives, catalysts, and phosphors. Recently, it has been widely used as a chemical mechanical abrasive for selective polishing of semiconductor substrates. Such cerium oxide powder is usually prepare...

AI Technical Summary

Problems solved by technology

Therefore pulverized containing Pr 6 o 11 The particle size distribution of the cerium oxide powder formed by the cerium oxide is not uniform, so not only the physical properties are adversely affected, when the cerium oxide particles are used as the abrasive to manufacture the CMP slurry, the grinding object ground by the above CMP There will be many scratches (for example, there are 4 to 15 scratches in an 8-inch wafer (wafer) to be polished), so there will be a problem of low quality of electronic products manufactured using the above-mentioned wafer (wafer)