The anodization reaction of SiC using HF solution makes a porous silic
on carbide (PSC) layer develop. The luminescence behavior of PSC, howe
ver, is somewhat different from that of porous Si in that the so-calle
d blue shift is not observed. Though the quantum confinement effect is
said to be responsible for light emission in porous SiC, the surface
state of PSC plays an important role. The effects of thermal annealing
under various atmospheres on the luminescence properties were studied
. Some spectroscopic analyses were adopted to elucidate the surface ch
emistry of PSC. The surface of PSC, which seems to be an origin of the
luminescence, had C-H termination but Si-H or Si-O bonds were not det
ected. X-ray photoelectron spectroscopy analysis also showed that the
Si-O bond that usually exists on the surface of bulk SiC was depressed
and a strong peak assigned to -CH- appeared. The oxidation treatment
reconstructed the Si-O bonds on the PSC surface, and this surface depr
essed the luminescence. Two other thermal treatments also depressed th
e PL spectra from the higher energy region, which is due to alternatio
n from C-H to C-C on the surface.