1results about How to "Reduce hard agglomerates" patented technology

The application discloses a colloidal cerium oxide polishing liquid and a preparation method thereof, and steps are as follows: S1. Dissolving a soluble cerium salt in deionized water, and respectively dissolving a surfactant, a suspension aid and an imidazole modifier in the deionized water and stirring and clarifying, mixing all the solutions, and performing ultrasonic stirring and high-pressure homogenizer circulation treatment to prepare a modified reaction precursor; S2. Continuously stirring the precursor, adding a precipitant at a uniform speed, and stirring after aging by heating to form a colloidal cerium oxide nanosphere solution with a nanosphere appearance; S3. Centrifuging the solution, washing and freeze-drying the solid to obtain a cerium oxide powder, mixing and stirring the powder and deionized water to disperse, and preparing the colloidal cerium oxide polishing liquid. The polishing liquid has uniform particle size, stable dispersion, a high SiO2 / Si3N4 selection ratio, can reduce wafer scratches, guarantee stable polishing performance, and is suitable for the chemical mechanical polishing demand of a semiconductor wafer shallow trench isolation process.