A kind of purposes of pyrogallic acid in silicon dioxide polishing

Abstract

The invention discloses the use of pyrogallic acid in silicon dioxide polishing. The pyrogallic acid is mixed with a chemical mechanical polishing liquid, the chemical mechanical polishing liquid includes cerium oxide abrasive particles, and the pyrogallic acid The concentration of the acid is 20-1000ppm, and the pH of the chemical mechanical polishing solution is 4.5. The invention can appropriately suppress the polishing rate of silicon dioxide by adding pyrogallic acid to the chemical mechanical polishing liquid, thereby avoiding butterfly-shaped defects on the surface of silicon dioxide during the polishing process and improving the quality of polished products.

Description

technical field [0001] The invention relates to the field of chemical mechanical polishing, in particular to the use of pyrogallic acid in silicon dioxide polishing. Background technique [0002] Chemical Mechanical Polishing (CMP) consists of chemical action, mechanical action, and a combination of both. It usually consists of a grinding table with a polishing pad, and a grinding head for carrying the wafer. The grinding head holds the wafer and presses the front side of the wafer against the polishing pad. When chemical mechanical polishing is performed, the grinding head moves linearly on the polishing pad or rotates in the same direction as the grinding table. At the same time, the slurry containing abrasive particles is dripped onto the polishing pad, and spreads on the polishing pad due to centrifugal action. The wafer surface is globally planarized under the dual action of mechanical and chemical. [0003] Cerium oxide is an important abrasive for CMP polishing fl...

AI Technical Summary

Problems solved by technology

However, this will increase the production cost of the polishing liquid

On the other hand, complete elimination of butterfly defects cannot be achieved without proper suppression of the polishing rate

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