Mechanical dispersion method for mixed polishing solution

Abstract

The invention discloses a mechanical dispersion method for a mixed polishing solution. The method includes, effectively dispersing grinding materials in the mixed polishing solution on the premise ofnot adding chemical dispersants and on the basis of the combination of mixing frequency, the medium-low frequency and high frequency ultrasound; selecting mixing frequency, wherein the medium-low frequency of the mixing frequency is 25-45 KHz, and the agglomerated grinding materials of tens of microns to several microns can be dispersed into the grinding materials with hundreds of nano particle sizes; re-dispersing the grinding materials dispersed by the medium-low frequency ultrasound to form a polishing grinding material of single particle, wherein the high-frequency ultrasonic frequency is600-900 kHz; distributing the dispersed polishing grinding material in the mixed polishing solution through stirring; aiming at the problem that the working temperature of the mixed polishing solutionis increased due to the fact that mechanical energy is converted into heat energy due to the long-time mechanical stretchable movement of a variable amplitude rod in an ultrasonic transducer, controlling an electromagnetic valve, introducing circulating cooling water into ultrasonic water for cooling in real time, and ensuing the mixed polishing solution at a temperature between 22-28 DEG C; anddefining an mixed polishing solution object, which comprises a body and capacity.

Description

technical field [0001] The invention relates to the field of physically dispersing nanoparticles, in particular to a mechanical dispersing method for mixing polishing liquid required by CMP. Background technique [0002] CMP, lithography, coating and etching together constitute the four basic processes of semiconductors. CMP technology started in the 1980s and was first proposed by IBM Corporation of the United States. In cutting-edge semiconductor technology, CMP has become an essential key process, and is currently the most direct and effective planarization method. The main consumables required for the CMP process include polishing pads and polishing fluids. The reason why the surface roughness of the workpiece / device surface can be greatly reduced after the CMP process is mainly based on the principle of CMP "soft grinding hard" [0003] The main consumables required for the CMP process include polishing fluid and polishing pads. The most commonly used polishing flui...

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Problems solved by technology

[0007] The purpose of the present invention is to solve the problem that it is difficult to find a universally suitable chemical dispersant for the mixed polishing liquid, or the problem that the medium and low frequency ultrasound cannot effectively disperse the abrasive in the mixed polishing liquid, and to provide a kind of mixing liquid required for CMP. Mechanical dispersion method of polishing liquid

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