Revealing the mechanisms for inactive rolling and wear behaviour on chemical mechanical planarization

VT Nguyen and TH Fang, APPLIED SURFACE SCIENCE, 595, 153524 (2022).

DOI: 10.1016/j.apsusc.2022.153524

The paper examines the influences of abrasive conditions, silica thickness, and motion parameters on the polishing process of a silicon substrate covered by a thin silica film. The silica film minimizes the direct collision of the abrasive on the silicon substrate. During the polishing process, the adhesion phenomenon plays the main role in atomic removal. Notably, the abrasive sliding motion can generate an inactive rolling motion. The inactive rolling motion can be used to explain the stick-slip motion by showing the system of periodic high-strain marks. In rolling, the deformation behaviors of the workpiece rely on the correspondence between the rolling and the moving speeds. In the fixed diamond abrasive (FDA) cases, the atomic sticking rate is lower but the workpiece deformation is higher than the loose diamond abrasive (LDA) cases. Besides, the FDA cannot create the inactive rolling motion and the stick-slip motion as the LDA. In general, the paper points out the existence of the inactive rolling motion and its role in the atomic removal process through the stick-slip motion phenomenon at the nanoscale, the advantage of this type of motion in a conventional chemical mechanical polishing (CMP) process, and the padding role of the silica layer.

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