Polishing solution used for planarization of dielectric material

Abstract

The invention discloses polishing solution used for planarization of a dielectric material. The polishing solution contains an abrasive material, a polishing accelerator, a surfactant and multi-fatty alcohol. The polishing method can reduce or prevent problems of drying, caking and the like in the using process, the requirement on moisture preservation of equipment is reduced, and the polishing solution has higher silicon dioxide removing rate and better surface pollutant index.

Description

technical field [0001] The invention relates to a polishing liquid used for flattening medium materials, in particular to a polishing liquid containing abrasives, polishing accelerators, surfactants and polyhydric fatty alcohols. Background technique [0002] In the chemical mechanical polishing of silica as a dielectric material, silicon-based abrasive particles are usually used, including fumed silica aqueous dispersion or silica sol particles. Since the silicon in the dielectric material is tetravalent silicon, it is difficult to accelerate its removal through oxidation-reduction reactions, and the removal of the material can only be promoted by strengthening the hydration of the silicon dioxide surface. At present, there are two types of commercial silica polishing fluids, one is the use of fumed silicon dioxide aqueous dispersion, the other is the use of silica sol. The two abrasives have their own disadvantages, but the common feature is that they have a relatively hi...

AI Technical Summary

Problems solved by technology

In addition, due to the large specific surface area of ​​nanoparticles, they are in a metastable state, and are easily agglomerated into balls, which eventually cause dry agglomeration.

Dry agglomerated abrasive particles are easy to fall off and mix in the slurry under vibration and stirring conditions, causing micro-scratches on the polished surface, and in severe cases, deep defects, resulting in some devices on the wafer surface. Open circuit or damage, so how to delay or avoid this phenomenon of dry agglomeration is also an important topic of dielectric material polishing fluid

At present, there is no relevant literature report. The purpose of the present invention is to slow down the evaporation of water, keep the liquid state of the slurry on the wall of the device, and slow down the drying process through chemical methods, that is, by adding water-locking and moisturizing components in the polishing liquid. The speed of the block can reduce similar problems in the polishing process without affecting the polishing rate and polishing selectivity