CERIUM OXIDE POWDER AND CERIUM OXIDE-CONTAINED DISPERSANT FOR POLISHING OF SEMICONDUCTOR SUBSTRATE

• Main Authors: KATUSIC, STIPAN, STAAB, EDWIN, KRESS, PETER, KRAEMER, MICHAEL, HEBERER, STEFAN, KROELL, MICHAEL
• Format: Patent
• Language: English; Korean
• Published: 28.02.2005
• Edition: 7
• Subjects: ADHESIVES; CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY; CHEMISTRY; COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM,CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THERARE-EARTH METALS; DYES; INORGANIC CHEMISTRY; MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FORELSEWHERE; METALLURGY; MISCELLANEOUS APPLICATIONS OF MATERIALS; MISCELLANEOUS COMPOSITIONS; NATURAL RESINS; PAINTS; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; POLISHES; THEIR RELEVANT APPARATUS; TRANSPORTING

PURPOSE: Provided is a method for preparing cerium oxide(CeOx) powder and CeOx-contained dispersant with high stability for use in polishing of semiconductor substrates. CONSTITUTION: The polycrystalline cerium oxide powder, CeOx (1.5 < x < 2), has 70-150m¬2/g of specific surface area, 5-20nm of primary particle diameter, 20-100nm of agglomerate diameter, and 0.4-0.6ml/g of mesopore volume, wherein more than 68% of primary particles are in the range of 0.6m - 1.4m, more than 70% of agglomerates have the surface area less than 1500nm¬2. The cerium oxide powder contains less than 500ppm of sodium and less than 0.1wt.% of carbon. Also, the cerium oxide powder is prepared by the following steps of: preparing an aerosol from the solution containing 2-40wt.% of cerium compound, changing into cerium oxide by gas(air) and oxidation; preparing flames from primary air such as H2-contained combustible gas, air or air/O2 ; pouring secondary air, two times the amount of primary air, into a reaction chamber, keeping lambda λ, 1.1 <= lambda λ<= 1.5, wherein λ is calculated by dividing the total fraction of O2 in primary/secondary air and atomizing gas with the amount of oxidizing cerium compound and O2-contained combustible gas, 55m/s of release speed of liquid drop from atomizer to reaction chamber; cooling reaction mixtures to 100-200deg.C. The CeOx-contained dispersant contains 2-20wt.% of CeO2, having average diameter of agglomerates(d50) less than 200nm, in 0.1-50wt.%(based on CeOx) of dispersant such as organic polymer, non-ionic surfactant or amine.