Atomic-level flatness on oxygen-free copper surface in lapping and chemical mechanical polishing

• DOI: 10.1039/d2na00405d
• Publication Date: 2022-08-22T08:12:55Z
• Authors: Dongdong Liu; Zhenyu Zhang; Jiajian Feng; Zhibin Yu; Fanning Meng; Guanghong Xu; Jianmei Wang; Wei Wen; Wei Liu
• Keywords: Chemical Mechanical Planarization; Lapping; Flatness (cosmology); Surface finishing

Oxygen-free copper (OFC) serves as a core component of high-end manufacturing, and requires high surface quality. It is always significant challenge to manufacture high-quality atomic-level surfaces. In this study, SiO2 nanospheres with good dispersibility were prepared late-model environmentally friendly chemical mechanical polishing (CMP) slurry was developed. The CMP consists nanospheres, CeO2 H2O2, NaHCO3, polyaspartic acid deionized water. After CMP, the average roughness (Sa) OFC wafer reached 0.092 nm an area 50 × μm2. Atomic-level flatness on oxygen-free acquired, which has never been reported before. Moreover, removal mechanism abrasive particles reactions during lapping are proposed in detail. thickness composition damaged layer after analyzed. lapping-damaged lattice distortion region, moiré fringes, grain boundary, superlattice edge dislocations, polishing-damaged contains handful stacking faults single-layer or multi-layer atoms. action involves three reactions: oxidation, corrosion chelation. processing method its mechanistic explanation pave way for fabrication high-performance surfaces use vacuum, aerospace, military electronic industries.