Comparison of C face (000 1¯) and Si face (0001) of silicon carbide wafers in femtosecond laser irradiation assisted chemical–mechanical polishing process

• Published in: Applied physics. A, Materials science & processing Vol. 128; no. 12
• Main Authors: Chen, Yuan-Di, Liu, Hsiang-Yi, Cheng, Chiao-Yang, Chen‬, ‬Chih-Chun
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.12.2022; Springer Nature B.V
• Subjects: Ablation; Applied physics; Characterization and Evaluation of Materials; Chemical-mechanical polishing; Condensed Matter Physics; Femtosecond pulsed lasers; Fluence; Graphitization; Irradiation; Laser beams; Lasers; Machines; Manufacturing; Material removal rate (machining); Materials science; Nanotechnology; Optical and Electronic Materials; Periodic structures; Physics; Physics and Astronomy; Polaritons; Processes; Pulse duration; Scratch hardness; Silicon carbide; Surfaces and Interfaces; Thickness; Thin Films; Silicon carbide; Laser; Chemical–mechanical polishing
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-022-06111-w

Silicon carbide (SiC) has extremely high hardness (Mohs hardness: 9.3) and high chemical stability; thus, it is quite difficult to achieve a high material removal rate in the chemical–mechanical polishing (CMP) process. This paper presents a method to accelerate the CMP process by irradiating SiC with a femtosecond laser. The effects of laser fluence and pulse duration on the C face and Si face modification are discussed. The ablation threshold of the C face is lower than that of the Si face. After laser irradiation, the thicknesses of laser-induced periodic structures of the C face and Si face are about 1 µm due to the optical interference effect between the incident femtosecond laser beam and the surface plasmon polaritons. SiC surfaces after laser irradiation present graphitization. Moreover, the hardness of the C face of laser-irradiated SiC samples is higher than that of the Si face in the same laser fluence. In the CMP process, the material removal rates of the C face and Si face of SiC samples after laser irradiation exhibited an improvement of 77% and 207%. This study reveals the advantages of femtosecond laser in the CMP process.