半导体碳化硅(4H-SiC)材料具有硬度高、脆性大、化学性质稳定等特点,一般使用化学机械抛光工艺来加工4H-SiC以获得超光滑平坦表面.湿法氧化作为单晶4H-SiC化学机械抛光的重要过程,直接影响着化学机械抛光的速率和表面质量.本文综述了目前单晶4H-SiC湿法氧化的研究现状,讨论了4H-SiC湿法氧化工艺所选用的氧化剂,如KMnO4、H2O2、K2S2O8等.在此基础上,进一步总结了常用的氧化增效方法,如光催化辅助氧化、电化学氧化、芬顿反应等,并从理论计算的角度分析了单晶4H-SiC湿法氧化的机理,最后展望了4H-SiC湿法氧化未来的研究方向.
Semiconducting silicon carbide(4H-SiC)exhibits characteristics of high hardness,notable brittleness,and excellent chemical stability.The commonly employed technique for achieving an ultra-smooth and flat surface is chemical mechanical polishing(CMP),which is utilized to process the 4H-SiC surface.Wet oxidation,as an important process of chemical-mechanical polishing of single-crystal 4H-SiC,directly affects the rate and surface quality of CMP.This paper provides a comprehensive overview of the current research status of wet oxidation of single-crystal 4H-SiC.It discusses the oxidants used in the wet oxidation of 4H-SiC,such as KMnO4,H2O2,K2S2O8.Based on this,it further summarizes commonly employed oxidation-enhancement methods,including photocatalytic-assisted oxidation,electrochemical oxidation,and Fenton reaction.The mechanism of wet oxidation of single-crystal 4H-SiC is analyzed from the aspect of theoretical calculation,and the future research direction of wet oxidation of 4H-SiC is proposed.