单晶SiC电化学腐蚀及化学机械抛光

通过电化学工作站对4英寸(1英寸=2.54 cm)n型单晶SiC(4H-SiC)进行电化学腐蚀特性研究,采用36GPAW-TD单面抛光机对其Si面和C面进行了化学机械抛光(CMP)。结果表明,采用H2O2和NaClO作为氧化剂,均可促进SiC的电化学腐蚀并提高其抛光去除速率,其促进作用与氧化剂浓度和抛光液的pH值密切相关。选择含体积分数5%的H2O2、pH值为12的SiO2抛光液对SiC进行CMP,得到的Si面抛光速率可以达到285.7 nm/h。在含H2O2抛光液中引入适量的NaNO3和十二烷基硫酸钠,SiC表现出较高的腐蚀电位绝对值和去除速率。在H2O2和NaClO抛光液体系中,SiC的去除速率与其腐蚀电位的绝对值正相关,该结果对实际应用有一定的借鉴意义。

Electrochemical Corrosion and Chemical Mechanical Polishing of Single Crystal SiC

The electrochemical corrosion characteristics of the 4 inch(1 inch=2.54 cm) n-type single crystal SiC(4 H-SiC) were studied by the electrochemical workstation, and the 36 GPAW-TD single side polisher was used in the chemical mechanical polishing(CMP) of the Si-and C-face of SiC, respectively. The results show that the use of H2O2 and NaClO as oxidants can promote the electrochemical corrosion of SiC and improve its polishing removal rate. The promotion is closely related to the concentration of the oxidant and the pH value of the slurry. The Si surface polishing rate of SiC obtained by CMP of SiO2 slurry with a volume fraction of 5% H2O2 and a fixed pH value of 12 can reach 285.7 nm/h. The introduction of an appropriate amount of NaNO3 and sodium lauryl sulfate in the H2O2 slurry contributes to a high absolute value of corrosion potential and removal rate of SiC. In the H2O2-and NaClO-based slurry system, the removal rate of SiC is positively correlated with the absolute value of the corrosion potential, which has certain guiding significance in practical applications.