Electrochemical-assisted hybrid machining has been widely utilized for processing of single crystal SiC, which is a very promising next-generation semiconductor material for high power, high frequency and high temperature applications. With the aim of optimizing the machining process to achieve both high efficiency and high surface integrity, the electrochemical oxidation behaviors of 4H-SiC were experimentally investigated with varying the anodizing conditions from the aspects of electrolyte types, ionic concentration, potentials etc. in this study. Experimental results demonstrated that neutral solutions showed higher oxidation ability of 4H-SiC in comparison to acidic and alkaline electrolytes. 4H-SiC could be electrochemically oxidized in an extremely low concentration electrolyte, and mass concentration 1∼2% could achieve highest film thickness of 197nm and initial oxidation rate of 4.9nm/s. The oxidation rate increased exponentially at the initial stage of anodization before reaching saturation. Meanwhile, the oxidation process exhibited significant anisotropy, with the oxidation rate of C-face 5-15 times higher that of Si-face. On the other hand, the hardness of the electrochemically-oxidized 4H-SiC surface was reduced by more than 90%. It was also noticed that the micro morphology of oxidized surface was significantly influenced by the ion types in the electrolytes. Furthermore, the electrochemical oxidation mechanism of 4H-SiC were discussed based on the experimental findings. The OH^. radical was considered the main factor determining the oxidation process of SiC. The research results deepen the understanding of the electrochemical oxidation of SiC and provide insights for optimizing the electrochemical-assisted hybrid machining process.

电化学辅助混合加工已被广泛用于单晶SiC的加工，这是一种非常有前途的下一代半导体材料，适用于高功率，高频和高温应用。为了优化加工过程以实现高效率和高表面完整性，本研究从电解质类型，离子浓度，电势等方面，通过改变阳极氧化条件，对4H-SiC的电化学氧化行为进行了实验研究。 。实验结果表明，与酸性和碱性电解质相比，中性溶液显示出更高的4H-SiC氧化能力。4H-SiC可以在极低浓度的电解液中被电化学氧化，质量浓度为1-2％时，最高膜厚为197nm，初始氧化速率为4.9nm / s。在达到饱和之前，氧化速率在阳极氧化的初始阶段呈指数增长。同时，氧化过程表现出明显的各向异性，C面的氧化速率是Si面的5-15倍。另一方面，电化学氧化的4H-SiC表面的硬度降低了超过90％。还注意到，氧化表面的微观形态受到电解质中离子类型的显着影响。此外，根据实验结果对4H-SiC的电化学氧化机理进行了探讨。OH 在达到饱和之前，氧化速率在阳极氧化的初始阶段呈指数增长。同时，氧化过程表现出明显的各向异性，C面的氧化速率是Si面的5-15倍。另一方面，电化学氧化的4H-SiC表面的硬度降低了超过90％。还注意到，氧化表面的微观形态受到电解质中离子类型的显着影响。此外，根据实验结果对4H-SiC的电化学氧化机理进行了探讨。OH 在达到饱和之前，氧化速率在阳极氧化的初始阶段呈指数增长。同时，氧化过程表现出明显的各向异性，C面的氧化速率是Si面的5-15倍。另一方面，电化学氧化的4H-SiC表面的硬度降低了超过90％。还注意到，氧化表面的微观形态受到电解质中离子类型的显着影响。此外，根据实验结果对4H-SiC的电化学氧化机理进行了探讨。OH 电化学氧化的4H-SiC表面的硬度降低了90％以上。还注意到，氧化表面的微观形态受到电解质中离子类型的显着影响。此外，根据实验结果对4H-SiC的电化学氧化机理进行了探讨。OH 电化学氧化的4H-SiC表面的硬度降低了90％以上。还注意到，氧化表面的微观形态受到电解质中离子类型的显着影响。此外，根据实验结果对4H-SiC的电化学氧化机理进行了探讨。OH^。自由基被认为是决定SiC氧化过程的主要因素。研究结果加深了对SiC电化学氧化的理解，并为优化电化学辅助混合加工工艺提供了见识。