Characterization and dressing effect of CMP diamond disc conditioner with ordered abrasive distribution

Abstract

With the advent of the 5G information age, the production and processing of computer chips has attracted people's attention. In order to adapt to the rapid development in the field of chip manufacturing, high requirements are placed on chemical mechanical planarization (CMP). Among them, the porous structure on the surface of the polishing pad is easily blocked and loses its performance during the use of the polishing pad. Therefore, the use of diamond disc conditioner to dress the polishing pad in the CMP process is an indispensable part. In this paper, a new method of measuring the dressing disc is proposed, after the wax block is melted, it solidifies on the surface of the dressing disc to obtain the protrusion height of the grains, this method has more advantages than measuring with an optical microscope because of the error caused by the diffuse reflection of the microscope. For diamond conditioners used in the experiments, the dressing trajectory of abrasive grains is simulated, which is the basis on choosing the experimental method, and the material removal rate model of the polishing pad is established. In addition, the diamond conditioners with orderly distributed abrasive grains are used to dress the polishing pad after polishing silicon wafer two hours, the discs can remove the blocking material on the surface of the polishing pad after dressing 30 minutes, the dressing effect and efficiency of the diamond disc with grain size of 100µm is more obvious. The surface roughness and the liquid contact angle of the polishing pad before and after dressing are measured, after a period of conditioning, they can be restored to a state similar to that of the new polishing pad.