Research progress in novel chemical–mechanical synergistic enhanced polishing methods for silicon carbide substrates

Silicon carbide (SiC), as a third-generation wide bandgap semiconductor material, possesses excellent thermal stability, electrical performance, and corrosion resistance. Its application fields are extremely extensive, such as integrated circuits, new energy, industrial manufacturing, smart vehicles, 5G communications, etc. SiC substrates are regarded as the foundation of high-performance semiconductor device manufacturing, and the surface quality influences the device performance directly. With the continuous improvement in device precision and reliability requirements, achieving atomic-level surface flatness (R_a < 0.5 nm) in SiC substrate processing has become a critical goal. However, the high hardness and chemical inertness of SiC pose significant challenges to conventional chemical mechanical polishing (CMP) techniques, which struggle to balance the material removal rate and surface quality effectively. This paper provides a systematic review of commonly used enhanced polishing techniques for SiC-CMP, including ultraviolet photocatalysis, mixed abrasives, electrochemical methods, and ultrasonic-assisted polishing. It analyzes the advantages, limitations, and current application status of each technology. This paper places particular emphasis on the research progress of novel chemical-mechanical synergistic enhanced polishing technologies, which aim to improve both machining efficiency and surface quality. Finally, it discusses the technical challenges and future development directions faced by these emerging technologies.