PURPOSE: To provide a polishing method capable of making the surface of the object to be polished flat without scratching the surface of a workpiece and provide a solvent for polishing liquid used for polishing a film made of SiO2.
CONSTITUTION: When polishing the SiO2 film of a wafer surface, solvent for polishing liquid, which includes fine particles of SiO2, and colloidal silica (the diameter of particles is 0.01 to 0.1μm) are stored in separate containers. These are mixed one hour before polishing to make grinding liquid, and the grinding liquid thus made is used for mechanochemical polishing. Time required for mixing through polishing is adjusted according to etching rate. As a result, the surface can be made flat without scratching the surface of SiO2 film. This serves to reduce micro roughness.
KAWAI YUKIO
MORITA ETSURO
OKADA CHIZUKO
MITSUBISHI MATERIALS CORP