Research on the molecular scale material removal mechanism in chemical mechanical polishing

This paper investigates a novel molecular scale material removal mechanism in chemical mechanical polishing (CMP) by incorporating the order-of-magnitude calculations, particle adhesion force, defect of wafer, thickness of newly formed oxidized layer, and large deformation of pad/particle not discussed by previous analysis. The theoretical analysis and experimental data show that the indentation depth, scratching depth and polishing surface roughness are on the order of molecular scale or less. Therefore, this novel mechanism has gained the support from wide order-of-magnitude calculations and experimental data. In addition, with the decrease in the particle size, the molecular scale removal mechanism is plausibly one of the most promising removal mechanisms to clarify the CMP polishing process. The results are useful to substantiating the molecular-scale mechanism of the CMP material removal in addition to its underlying theoretical foundation.