COMPOSITION FOR POLISHING SILICON NITRIDE AND METHOD FOR CONTROLLING SELECTIVITY USING SAME

摘要

A composition for polishing silicon nitride, which contains a colloidal silica and a polishing aid that is composed of a phosphoric acid compound and a sulfuric acid compound.  By additionally containing an oxidizing agent, the composition controls a first selectivity that is the ratio of the polishing rate of a metal film to the polishing rate of a silicon nitride film, as well as a second selectivity that is the ratio of the polishing rate of an oxide insulating film to the polishing rate of the silicon nitride film.