Colloidal nano-abrasives and slurry for chemical-mechanical polishing of semiconductor materials

Colloidal nano-abrasives and slurry for chemical-mechanical polishing of semiconductor materials

Chemical-mechanical polishing or planarization (CMP) is one of the key fabrication processes in the semiconductor industry. Colloidal nano-abrasives with different particle sizes are required for slurries in different CMP processes of semiconductor. So the controlled-growth of particle sizes, particle size distribution and their application become more and more important. In this paper, based on additional experiments and analysis, colloidal nano-abrasives with different particle sizes were prepared by ion-exchange and hydrothermal processes, and their size and stability were characterized by transmission electron microscope (TEM) and a Zeta potential instrument. Results show that colloidal nano-abrasives with diameters of 10-20 nm, 50-70 nm, 80-90 nm were obtained, and the zeta potential (less than −45 mV) also illustrates that the colloidal nano-abrasives was of high stability. One kind of colloidal nano-abrasives with average diameter of 80-90 nm was used to prepare one polishing slurry for silicon wafers. The polishing rate was more than 600 nm/minute and the root mean square (RMS) of surface roughness for polished silicon wafers was less than 0.4 nm, which shows that this type of slurry with the self-made colloidal abrasives not only gives higher polishing rate, but also provides less surface roughness.

Chemical-mechanical polishing or planarization (CMP) is one of the key fabrication processes in the semiconductor industry. Colloidal nano-abrasives with different particle sizes are required for slurries in different CMP processes of semiconductor. So the controlled-growth of particle sizes, particle size distribution and their application become more and more important. In this paper, based on additional experiments and analysis, colloidal nano-abrasives with different particle sizes were prepared by ion-exchange and hydrothermal processes, and their size and stability were characterized by transmission electron microscope (TEM) and a Zeta potential instrument. Results show that colloidal nano-abrasives with diameters of 10-20 nm, 50-70 nm, 80-90 nm were obtained, and the zeta potential (less than −45 mV) also illustrates that the colloidal nano-abrasives was of high stability. One kind of colloidal nano-abrasives with average diameter of 80-90 nm was used to prepare one polishing slurry for silicon wafers. The polishing rate was more than 600 nm/minute and the root mean square (RMS) of surface roughness for polished silicon wafers was less than 0.4 nm, which shows that this type of slurry with the self-made colloidal abrasives not only gives higher polishing rate, but also provides less surface roughness.