Modeling of material removal rate considering the chemical mechanical effects of lubricant, oxidant, and abrasive particles for aluminum chemical mechanical polishing at low pressure

Lubricants are widely used for aluminum (Al) chemical mechanical polishing (CMP) to eliminate surface scratch damage. Understanding of the fundamental of CMP material removal mechanisms including lubrication is crucial to offer insights into the control and optimization of the polishing process. This paper proposes a novel material removal rate (MRR) model based upon molecular-scaled removal mechanism, micro-contact force equilibrium theory, chemical reaction kinetics and diffusion effects, with further considering the lubricant effect on the removal rate at low polishing pressure. Moreover, the presented model also clarifies the nonlinear dependence of removal rate on lubricant concentration, oxidizer concentration, and abrasive concentration. The model prediction results could provide qualitative insights into the influence of lubricant concentration, oxidizer concentration, and abrasive concentration on MRR, thus providing theoretical foundation and support for delineating the Al-CMP process at low pressure. Finally, it is found that the theoretical predictions possess qualitative agreement with the experimental results.