Chemical mechanical polishing slurry and preparation method thereof

Abstract

The invention discloses chemical mechanical polishing slurry and a preparation method thereof, and relates to the technical field of polishing. The chemical mechanical polishing slurry comprises the following components in percentage by mass: 15-25 parts of inorganic polishing powder, 5-10 parts of an oxidizing agent, 0.1-1 part of a surfactant, 0.1-1 part of a defoaming agent, 1-2 parts of a thickening agent, 1-2 parts of a pH regulator and 100 parts of deionized water, wherein CeO2-SiO2 composite polishing powder is adopted as the inorganic polishing powder, the oxidizing agent is nitric acid or sodium dichromate; and the PH value of the polishing slurry is 7-8. According to the invention, CeO2-SiO2 composite polishing powder adopts CeO2 and SiO2 in different proportions; and the test results show that the high polishing amount can be obtained, the respective defects of CeO2 and SiO2 are abandoned, the advantages are integrated, and the CeO2-SiO2 composite polishing powder has the advantages of being high in grinding amount, best in polishing capacity, long in service life, high in polishing precision, easy to clean, low in cost and high in polishing efficiency.

Description

technical field [0001] The invention belongs to the technical field of polishing, in particular to a chemical mechanical polishing slurry and a preparation method thereof. Background technique [0002] Chemical Mechanical Polishing is abbreviated as CMP, which is a combined technology of mechanical grinding and chemical etching. With the help of the grinding effect of ultra-fine particles and the chemical corrosion of slurry, it can be used on the surface of the polished medium, such as single crystal silicon wafers, integrated circuit oxide films, Forming a clean and flat plane on the metal film has become the leading technology in the semiconductor processing industry. Traditional mechanical polishing is an important step in the SiC wafer processing process. The quality of the processed wafer directly affects the surface quality of the product and the progress of subsequent industrial processes. The traditional mechanical polishing liquid is consistent with the direct use ...

AI Technical Summary

Problems solved by technology

Traditional mechanical polishing is an important step in the SiC wafer processing process. The quality of the processed wafer directly affects the surface quality of the product and the progress of subsequent industrial processes. The traditional mechanical polishing liquid is consistent with the direct use of silicon dioxide polishing liquid. The disadvantage is the removal rate Low, long processing time, in the actual production process, it is easy to cause a lot of scratches on the surface of the processed object, not suitable for industrial sound field

[0003] Silica hydrosol is currently the most representative polishing slurry for CMP, and the more common ones include the use of polishing powders such as silicon oxide, iron oxide, zirconia, aluminum oxide, chromium oxide, and cerium oxide to prepare polishing slurry. However, since these polishing powders have different hardness, different polishing capabilities, and different use costs, the corresponding use scenarios and frequencies are different.

According to the comparison of polishing ability, it can be clearly known that the grinding amount and polishing ability of cerium oxide are the best, the polishing ability of zirconia and titanium oxide is poor, and the polishing ability of titanium oxide is the second; It is the most widely used in the scene. Compared with other polishing powders, cerium-based rare earth polishing powders have many outstanding advantages, such as good crystal form, high chemical activity, smaller particle size compared with other polishing powders, long service life, and excellent polishing performance. The advantages of high precision, easy cleaning and high polishing efficiency, but because the rare earth is rare, the cost is high, the price is expensive, and the dispersion is not good, and it is easy to agglomerate; Combining silicon oxide polishing powder with cerium oxide and adjusting its material formula to obtain good polishing efficiency and corresponding relatively low cost has great potential for the market application of polishing slurry

Images