Abstract: We give the first report on the experimental investigation of a p-β -FeSi₂/n-4H-SiC heterojunction. A p-β -FeSi₂/n-4H-SiC heterojunction near-infrared photodiode was fabricated on 4H-SiC substrate by magnetron sputtering and rapid thermal annealing (RTA). Sharp film-substrate interfaces were confirmed by scanning electron microscopy (SEM). The current density-voltage and photoresponse characteristics were measured. The measurements showed that the device exhibited good rectifying properties. The photocurrent density was about 1.82 mA/cm² at a bias voltage of -1 V under illumination by a 5 mW, 1.31 μ m laser, and the dark current density was approximately 0.537 mA/cm². The detectivity was estimated to be 8.8 × 10⁹ cmHz^1/2/W at 1.31 μ m. All of the measurements were made at room temperature. The results suggest that the p-β -FeSi₂/n-4H-SiC heterojunctions can be used as near-infrared photodiodes that are applicable to optically-activated SiC-based devices.

Key words: β -FeSi₂, magnetron sputtering, p-β -FeSi₂/n-4H-SiC heterojunction, photoelectric properties