Electrochemistry of anodic etching of 4H and 6H–SiC in fluoride solution of pH 3

✍ Scribed by D.H. van Dorp; J.J.H.B. Sattler; J.H. den Otter; J.J. Kelly

• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 346 KB
• Volume: 54
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/j.electacta.2009.05.086

✦ Synopsis

Electrochemical etching of single-crystal SiC rotating disk electrodes in fluoride solution was studied at pH 3. Anodic dissolution and passivation are observed for p-type electrodes in the dark and for n-type electrodes under illumination. The dissolution of p-type (0 0 0 1) 4H-SiC is found to be under mixed transport/kinetic control; the diffusion current is first order in fluoride concentration. Polishing of p-type electrodes can be achieved at rates up to 5.8 m/min. Porous etching was not observed in this case. The surface finish of n-type (0 0 0 1) 4H and 6H-SiC depends on the experimental conditions; both uniform and porous etching are observed. The results are compared with those of Si under comparable conditions.