ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Thick p-type porous 6H SiC layers were fabricated by anodization of p-type 6H SiC bulk crystals in dilute HF. Striking differences are observed in the reststrahl region room-temperature reflectance of these porous layers compared to that of bulk 6H SiC crystals. Instead of the single broad band reflectance spectrum typically observed in bulk 6H SiC, a two-band reflectance spectrum is observed. Several effective medium models, based on different morphologies of the component materials, 6H SiC and air, are used to obtain the frequency-dependent dielectric function of porous SiC from which calculated reflectance spectra are generated. The best match between measured and calculated spectra is obtained for a Maxwell–Garnett model with SiC acting as the host material and air cavities acting as the inclusion material. The model reproduces the two reflectance band structure observed in the measured reflectance of the porous SiC layers. The differences in the reststrahl region reflectance spectra of the porous SiC layers, compared to bulk SiC, are associated with polarization effects introduced by the cavities combined with a mean field average of interactions among the cavities. © 1996 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.363046
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