Ultraprecision machining for single-crystal silicon carbide wafers: State-of-the-art and prospectives

Silicon carbide (SiC) has a wide range of application prospects for the excellent characteristics. However, its high hardness, brittleness, and chemical inertia improve the processing difficulty, which restricts the popularization and application of single-crystal SiC semiconductor devices. This paper introduces the research progress of SiC from two parts: material removal mechanism and ultraprecision machining technology. The material removal and damage formation mechanism of SiC at home and abroad, as well as the research progress of lapping, polishing technology and ultraprecision grinding technology are introduced in detail. The analysis shows that there are some differences in the removal mechanisms of SiC studied by different scholars. In addition, the lack of a reasonable theoretical model for surface integrity hinders the selection of efficient and low-damage process parameters for grinding SiC wafers. In terms of single crystal SiC ultraprecision machining, the more mature machining methods at this stage mainly go through three steps: double-sided lapping, single-sided lapping and chemical mechanical polishing. The machining efficiency and surface integrity of each step affect the production efficiency and scrap rate of the final product. As SiC wafers develop towards larger sizes, ultraprecision grinding technology, which utilizes workpiece rotation grinding principles, emerges as an efficient and low-damage machining method of SiC wafers, has the potential to replace the traditional lapping.