Room light anodic etching of highly doped n-type 4 H-SiC in high-concentration HF electrolytes: Difference between C and Si crystalline faces.
In this paper, we study the electrochemical anodization of n-type heavily doped 4 H-SiC wafers in a HF-based electrolyte without any UV light assistance. We present, in particular, the differences observed between the etching of Si and C faces. In the case of the Si face, the resulting material is mesoporous (diameters in the range of 5 to 50 nm) with an increase of the 'chevron shaped' pore density with depth. In the case of the C face, a columnar morphology is observed, and the etch rate is twice greater than for the one for the Si face. We've also observed the evolution of the potential for a fixed applied current density. Finally, some wafer defects induced by polishing are clearly revealed at the sample surfaces even for very short etching times.
GREMAN, UMR CNRS 7347, Université de Tours, 16 rue P, et M, Curie, Tours Cedex 2, 37071, France. gael.gautier@univ-tours.fr.
Gael
G
Gautier
Frederic
F
Cayrel
Marie
M
Capelle
Jérome
J
Billoué
Xi
X
Song
Jean-Francois
JF
Michaud