Chemically-induced active micro-nano bubbles assisting chemical mechanical polishing: Modeling and experiments

Abstract

The material loss caused by bubble collapse during the micro-nano bubbles auxiliary chemical mechanical polishing (CMP) process cannot be ignored. In this study, the material removal mechanism of cavitation in the polishing process was investigated in detail. Based on the mixed lubrication or thin film lubrication, bubble—wafer plastic deformation, spherical indentation theory, Johnson—Cook (J—C) constitutive model, and the assumption of periodic distribution of pad asperities, a new model suitable for micro-nano bubble auxiliary material removal in CMP was developed. The model integrates many parameters, including the reactant concentration, wafer hardness, polishing pad roughness, strain hardening, strain rate, micro-jet radius, and bubble radius. The model reflects the influence of active bubbles on material removal. A new and simple chemical reaction method was used to form a controllable number of micro-nano bubbles during the polishing process to assist in polishing silicon oxide wafers. The experimental results show that micro-nano bubbles can greatly increase the material removal rate (MRR) by about 400% and result in a lower surface roughness of 0.17 nm. The experimental results are consistent with the established model. In the process of verifying the model, a better understanding of the material removal mechanism involved in micro-nano bubbles in CMP was obtained.

Laser-Produced Cavitation Bubble Behavior in Newtonian and Non-Newtonian Liquid Inside a Rigid Cylinder: Numerical Study of Liquid Disc Microjet Impact Using OpenFOAM

“…This phenomenon has significant advantages besides its destructive effects, such as erosion, high noise, part damage, vibration, and efficiency loss, primarily occurring in engines and pumps. The dynamics of cavitation bubbles are commonly employed in various branches of engineering, including nanomaterials [ 1 , 2 ], chemical [ 3 , 4 ], mechanical [ 5 , 6 ], shipbuilding [ 7 , 8 ], ocean [ 9 , 10 , 11 ], environmental engineering [ 12 ], and important practical issues, such as surface cleaning [ 13 ]. In the medical field, this phenomenon can be used to break up kidney stones [ 14 ], deliver drugs and genes to cells [ 15 ], and treat cancerous tumors [ 16 ].…”