Slurryless electrochemical mechanical polishing of 4-inch 4H–SiC (0001) and (000–1) surfaces

Abstract

Silicon carbide (SiC) is a very promising next-generation semiconductor material for power device applications, and polishing technology plays an important role in improving the performance of electronics. In this regard, slurryless electrochemical mechanical polishing (ECMP) is a promising polishing technology for SiC wafer in obtaining high efficiency and high precision. In this study, slurryless ECMP of 4-inch 4H–SiC (0001) and (000–1) surfaces (Si and C faces) were investigated aiming to the industrial application. Anodic oxidation property, polishing characteristics, and mechanism of the Si and C faces in slurryless ECMP were compared and clarified. Based on the obtained results, two-step slurryless ECMP (i.e., ECMP with diamond polishing plate and then with ceria polishing plate) was conducted on 4-inch as-sliced Si and C faces. Additionally, 4-inch Si and C faces with peak-to-valley (PV) value less than 2 μm and overall surface roughness in nanometer order were obtained.