2results about How to "Improve polishing selectivity" 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.

The invention discloses a chemical mechanical polishing solution which comprises an epinephrine compound, the molecular structure of the epinephrine compound is # imgabs0 #, R1 is x, y-benzenediol or x, y, z-benzenediol, and x, y and z are numbers from 2 to 6; r2 and R3 are hydrogen atoms, alkane with the carbon number of 1-6 or alcohol with the carbon number of 1-6; and n is a number from 1 to 3. The invention provides a chemical mechanical polishing solution as well as a preparation method and application thereof, the polishing rate of silicon nitride can be inhibited while the polishing rate of the polishing solution to a silicon dioxide dielectric layer is increased, and the generation of dish-shaped grooves and scratches in the polishing process can be avoided or reduced.