ELECTRICAL-PROPERTIES AND FORMATION MECHANISM OF POROUS SILICON-CARBIDE

Variation of the preparation conditions of porous silicon carbide is s hown to have a strong effect on the structural and electrical properti es of the material obtained. A correlation has been observed between t he fiber size and resistivity of porous SiC, a decrease of fiber size results in a semi-insulating material due to Fermi-level pinning to su rface states. A model is proposed for the mechanism of fiber size self -regulation responsible for the porous material formation. The model r elates the blocking of the fiber dissolution process to the increase o f resistivity in a thin fiber due to Fermi-level pinning. We suggest t hat the Fermi-level pinning model is also applicable to the formation mechanism of porous silicon. (C) 1994 American Institute of Physics.