| 摘要 |
PURPOSE: Provided is an acidic polishing slurry for chemical-mechanical polishing of SI02 isolation layers with a high polishing selectivity in terms of the rate at which silica is removed compared to the rate at which silicon nitride is removed. CONSTITUTION: The acidic polishing slurry contains components: 0.1 to 5% by weight of a colloidal silica abrasive and 0.5 to 10% by weight of a fluoride salt. The polishing slurry is preferably used to polish a composite which contains silica and silicon nitride, particularly, to polish a dielectric film, such as a silica film, which is formed on a silicon nitride film, the silicon nitride film being used as a stop layer. In the polishing slurry, the colloidal silica abrasive is preferably present in a quantity of from about 0.1 to about 3.5% by weight, and the fluoride salt is present in a quantity of from about 1 to about 6% by weight. The colloidal silica may have a mean particle size of 10 nm to 1 micrometer, preferably 20 nm to 100 nm.
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