Lg Chem, Ltd

Jang-Yul Kim

Seung-Beom Cho

Jong-Pil Kim

Myoung-hwan Oh

Jun-seok Nho

Min-Jin Ko

Dong-Mok Shin

Jun-Seok Noh

Myoung-Hwan Oh

The present invention relates to a CMP slurry that is able to reduce dishing generation, when it is applied to polishing or planarization of silicon oxide layer, for example, and a polishing method. The CMP slurry includes a polishing abrasive, a linear anionic polymer, a compound including a phosphoric acid group, and water, and the ratio of CMP polishing speed to a silicon oxide layer: CMP polishing speed to a silicon nitride layer is 30:1 to 50:1.

CMP slurry and a polishing method using the same

Disclosed is cerium oxide powder for a CMP abrasive, which can improve polishing selectivity of a silicon oxide layer to a silicon nitride layer and/or within-wafer non-uniformity (WIWNU) during chemical mechanical polishing in a semiconductor fabricating process. More particularly, the cerium oxide powder is obtained by using cerium carbonate having a hexagonal crystal structure as a precursor. Also, CMP slurry comprising the cerium oxide powder as an abrasive, and a shallow trench isolation method for a semiconductor device using the CMP slurry as polishing slurry are disclosed.

Cerium oxide powder, method for preparing the same, and CMP slurry comprising the same

Disclosed are cerium oxide powder for an abrasive; CMP slurry including the same; and a shallow trench isolation (STI) process using the CMP slurry. At least two kinds of cerium oxides prepared by using cerium carbonates having different crystal structures are mixed in an appropriate ratio and used as an abrasive for CMP slurry, thereby adjusting required polishing properties of the CMP slurry. Also, in a disclosed method of preparing a cerium carbonate, the crystal structure of the cerium carbonate can be easily controlled. Based on the finding that in a cerium oxide for an abrasive, the kind of improved polishing property depends on the crystal structure of a cerium carbonate, at least one from among polishing properties, such as the polishing rate of a silicon oxide layer, the polishing rate of a silicon nitride layer, the polishing selectivity between the silicon oxide layer and the silicon nitride layer, and WIWNU, can be adjusted by using at least two kinds of cerium oxides selected from the group including (i) a cerium oxide prepared by using a lanthanite-(Ce) crystal structured cerium carbonate, (ii) a cerium oxide prepared by using an orthorhombic crystal structured cerium carbonate, and (iii) a cerium oxide prepared by using a hexagonal crystal structured cerium carbonate, as an abrasive for CMP slurry, and adjusting the mixing ratio of the cerium oxides.

Cerium oxide powder for abrasive and CMP slurry comprising the same

The present invention relates to a method of preparing a cerium oxide powder for a CMP slurry and a method of preparing a CMP slurry using the same, and more particularly, to a method of preparing a cerium oxide powder for a CMP slurry and a method of preparing a CMP slurry using the same in which the specific surface area of the powder is increased by preparing a cerium precursor, and then decomposing and calcinating the prepared cerium precursor. The pore distribution is controlled to increase the chemical contact area between a polished film and a polishing material, thereby reducing polishing time while the physical strength of powder is decreased, which remarkably reduces scratches on a polished film.

Method for preparing of cerium oxide powder for chemical mechanical polishing and method for preparing of chemical mechanical polishing slurry using the same

In a method for preparing cerium carbonate powder by mixing a cerium precursor solution with a urea solution and carrying out a precipitation reaction, wherein the cerium carbonate powder has a hexagonal crystal structure, by using at least one type of organic solvent as a solvent for either or both the cerium precursor solution and the urea solution, and adjusting temperature of the precipitation reaction within a range of 120&#xb0; C. to 300&#xb0; C. Also, the method can yield cerium carbonate powder, cerium oxide powder from the cerium carbonate powder, and CMP slurry including the cerium oxide powder as an abrasive. In the method, urea as a precipitant can improve the uniformity of a reaction, and thus it is possible to easily and inexpensively obtain cerium carbonate powder with a hexagonal crystal structure without the danger by high-temperature high-pressure and the need for an expensive system in hydrothermal synthesis.

Method for preparing cerium carbonate powder using urea

Disclosed is a method for directly preparing cerium oxide powder in a solution phase by a) mixing a cerium precursor solution with a precipitant solution to cause a reaction; and b) performing oxidation treatment of the reacted solution, wherein at least one kind of pure organic solvent containing no water is used as a solvent for the cerium precursor solution as well as the precipitant solution to thereby prepare the cerium oxide powder, the particle size of which is adjusted to 50 nm to 3 &#x3bc;m. Cerium oxide powder obtained from the method and CMP slurry comprising the cerium oxide powder as a polishing agent are also disclosed. The method makes it possible to prepare cerium oxide powder with an average particle size of 50 nm or greater and high crystallinity, which is difficult to prepare by the conventional wet precipitation process, by using an organic solvent as a solvent in a wet precipitation process, and the so-prepared cerium oxide powder can be used as a polishing agent for CMP slurry even without being subjected to separate heat treatment.

Method for preparing cerium oxide powder using organic solvent and CMP slurry comprising the same

The present invention relates to cerium oxide powder and a process for producing the same. The cerium oxide powder of the invention, which is produced by mixing a cerium source such as cerium oxide, cerium hydroxide and cerium carbonate with an alkali metal compound, as flux, and performing high temperature treatment, may have a variety particle size while having spherical shape.

Cerium oxide powder and process for producing the same

In a method for preparing cerium carbonate powder by mixing a cerium precursor solution with a carbonate precursor solution and carrying out a precipitation reaction, wherein cerium carbonate is controlled to have an orthorhombic crystal structure, a hexagonal crystal structure or an orthorhombic/hexagonal mixed crystal structure, by using at least one type of organic solvent comprising at least two hydroxyl groups (OH) in molecular formula as a solvent for either or both the cerium precursor solution and the carbonate precursor solution, and varying a number of carbons or hydroxyl groups (OH) included in the molecular formula of the organic solvent. The method can easily and inexpensively obtain cerium carbonate powder with a desired crystal structure without the danger by high-temperature high-pressure and the need for an expensive system in hydrothermal synthesis.

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Daejeon, South Korea

Jang-Yul Kim