Aqueous alkaline (pH 10.8) slurries prepared from slurries with a particle size from 0.1-0.5 microns heated or autoclaved to increase abrasivity

摘要

Oxidizing agents are added to slurries of inorganic oxides which have been heated, e.g., autoclaved, to produce abrasive slurries which impart relatively equal polishing rates for conductive metal and insulating layers used to make semiconductor chips. A relatively flexible abrasive slurry in terms of its abrasivity is also provided by this slurry, thereby permitting the modification of a copper polishing slurry's abrasivity when a new insulating material is used to make a chip. When using this method, an increase in particle abrasivity of this slurry can be correlated with a decrease in particle surface area as determined by N2 adsorption (BET method) and abrasivity can be increased (or decreased) by heating the slurry to produce particles with a surface area determined to have the abrasivity desired. The method is particularly suitable for preparing silica-based abrasive slurries and the slurries prepared are particularly useful for polishing chips made with copper conductive circuits and silica-based insulating layers.