Silicon polishing composition, preparation method and application thereof

Abstract

The invention provides a silicon polishing composition as well as a preparation method and application thereof, the silicon polishing composition takes nano silicon dioxide colloid as a main polishing component, and piperazine substances and water-soluble organic weak acid containing furan rings are added as auxiliaries. The piperazine substance and the water-soluble organic weak acid containing the furan ring are simultaneously added into the silicon polishing composition to serve as the stability auxiliaries, the grinding material agglomeration can be effectively inhibited, the storage time and the service life of the polishing solution are prolonged, and compared with the prior art, the silicon polishing composition has obvious advantages.

Description

technical field [0001] The invention relates to the technical field of chemical mechanical polishing, in particular to a silicon polishing composition, a preparation method and an application thereof. Background technique [0002] Silicon is currently the most widely used semiconductor material and has played an irreplaceable role in the realization of human global informatization. High-purity monocrystalline silicon is mainly used as a substrate material in the manufacture of integrated circuits, and hundreds of millions of transistors with source, gate and drain are formed on its surface through photolithography, ion implantation, deposition and other processes, forming the entire chip. Cornerstone". With the emergence of VLSI, ULSI, and SLSI-level integrated circuits, the integration of chips continues to increase, and the feature size continues to decrease, so higher requirements are also placed on substrate wafers. [0003] There are two preparation methods for single...

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Problems solved by technology

However, the adsorption of anionic surfactants also increases the repulsion between the silica sol particles and the silicon wafer, and the surfactant also significantly weakens the sliding friction between the abrasive and the substrate, reducing the mechanical action during the polishing process, resulting in Decreased polishing rate

In addition, these substances will also introduce sodium ions, which will easily cause metal ion pollution on the surface of polished silicon wafers

[0006] Chinese patent applications CN201811627080.8 and CN201110002321.1 respectively propose to add silane coupling agents such as 3-aminopropyltriethoxysilane and methyltrimethoxysilane to the silicon polishing solution, and graft the surface of the silica sol particles with Sulfonic acid-based organics to improve the storage stability of the polishing solution, while reducing the residue of silica sol particles on the polishing surface, however, due to the nano-SiO 2 The graft coating of the surface molecular layer weakens its adsorption and carrying effect on reaction products such as silicate ions, and also has a significant adverse effect on the polishing rate.

However, the patent only mentions that the concentrated composition can be kept at 21°C for two weeks without precipitation. In actual production and use, the polishing composition is often not used for a short period of time after preparation, and its storage time may reach several months or even One year, so it is not only required that the composition does not precipitate during storage, but also that the average particle size increase due to abrasive agglomeration should be avoided to prevent changes in the consistency of the polishing rate

Therefore, even if piperazine substances are added as stabilizers of the polishing composition in the prior art, the stability of the polishing composition is far from the level of application only by adding such substances.

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