Surface micromorphology and nanostructures evolution in hybrid laser processes of slicing and polishing single crystal 4H-SiC  

作　　者：Yuhang Li Zhe Zhang Qi Song Haiyan Shi Yu Hou Song Yue Ran Wang Shunshuo Cai Zichen Zhang 

机构地区：[1]Microelectronics Instruments and Equipment R&D Center,Institute of Microelectronics,Chinese Academy of Sciences,Beijing 100029,China [2]International Research Centre for Nano Handling and Manufacturing of China,Changchun University of Science and Technology,Changchun 130022,China

出　　处：《Journal of Materials Science & Technology》2024年第17期235-244,共10页材料科学技术（英文版）

基　　金：supported by National Natural Science Foundation of China(No.62304249);a project funded by China Postdoctoral Science Foundation(No.2023M733704).

摘　　要：Slicing and post-treatment of SiC crystals have been a significant challenge in the integrated circuit and microelectronics industry.To compete with wire-sawing and mechanical grinding technology,a promis-ing approach combining laser slicing and laser polishing technologies has been innovatively applied to increase utilization and decrease damage defects for single crystal 4H-SiC.Significant material utiliza-tion has been achieved in the hybrid laser processes,where material loss is reduced by 75%compared to that of conventional machining technologies.Without any special process control or additional treat-ment,an internally modified layer formed by laser slicing can easily separate the 4H-SiC crystals using an external force of about∼3.6 MPa.The modified layer has been characterized using a micro-Raman method to determine residual stress.The sliced surface exhibits a combination of smooth and coarse appearances around the fluvial morphology,with an average surface roughness of over S_(a) 0.89μm.An amorphous phase surrounds the SiC substrate,with two dimensions of lattice spacing,d=0.261 nm and d=0.265 nm,confirmed by high-resolution transmission electron microscopy(HRTEM).The creation of laser-induced periodic surface nanostructures in the laser-polished surface results in a flatter surface with an average roughness of less than S_(a) 0.22μm.Due to the extreme cooling rates and multiple thermal cy-cles,dissociation of Si-C bonding,and phase separation are identified on the laser-polished surface,which is much better than that of the machining surface.We anticipate that this approach will be applicable to other high-value crystals and will have promising viability in the aerospace and semiconductor industries.

关 键 词：Laser polishing Silicon carbide Internal modification Laser slicing Surface quality Microstructure 

分 类 号：TG146.23[一般工业技术—材料科学与工程] TG665[金属学及工艺—金属材料]