AC IMPEDANCE SPECTROSCOPY OF Al/a-SiC/c-Si(p)/Al HETEROSTRUCTURE UNDER ILLUMINATION
Milan Perný – Vladimír Šály – Michal Váry – Miroslav Mikolášek – Jozef Huran – Juraj Packa
The amorphous silicon carbide/crystalline silicon heterojunction was prepared and analyzed. The current-voltage (I-V) measurements showed the barrier properties of prepared sample. Biased impedance spectra of Al/a-SiC/c-Si(p)/Al heterojunction under the standard illumination are reported and analyzed. AC measurements in the illuminated conditions were processed in order to identify electronic behavior using equivalent AC circuit which was suggested and obtained by fitting the measured impedance data. A phenomenon of negative capacitance/resistance in certain frequency range has been observed.
Keywords: PECVD, heterojunction, silicon carbide, equivalent AC circuit, complex impedance