Advances and Challenges in Chemical Mechanical Polishing of Silicon Carbide: Materials, Mechanisms, and Future Directions

Abstract

Silicon carbide (SiC), a third-generation wide bandgap semiconductor material, demonstrates immense potential in high-temperature, high-frequency, and high-power electronic devices. However, its exceptional hardness and chemical inertness present significant challenges in chemical mechanical polishing (CMP), particularly in achieving atomically flat surfaces without damage. SiC CMP faces core challenges such as low material removal rates (MRR < 1 μm/h), high risks of surface/subsurface damage, and substantial processing costs. This paper reviews SiC CMP research, addressing key challenges such as material properties, process mechanisms, slurry chemistry, and emerging technologies. The paper emphasizes the synergistic interaction between mechanical abrasion and chemical reactions, exploring the impact of polishing parameters such as pressure, slurry composition, and pH on polishing performance and surface chemistry. Recent breakthroughs, including catalytically assisted CMP (e.g., Fenton reaction) and externally field-assisted techniques (e.g., electrochemical, plasma-assisted), significantly improve surface oxidation by generating reactive oxygen species (e.g., ·OH) in situ, resulting in higher MRR (1-4 μm/h) and ultra-smooth surfaces (Ra < 0.1 nm). The paper also reviews the critical roles of oxidants (H2O2, KMnO4), abrasives (SiO2, CeO2), and additives in slurry development. It outlines future research directions for SiC CMP, including the development of high-efficiency catalytic systems, integration of external field-assisted techniques, AI-driven process optimization, and green polishing technologies. Despite persistent challenges, ongoing advancements in interfacial reaction mechanisms and novel approaches will drive CMP technology toward broader applications in SiC-based devices, supporting the continued growth of high-performance semiconductor industries.