InAlAs/InGaAs metal-semiconductor-metal photodiodes heteroepitaxially grown on Si substrates

Abstract

To study performance and reproducibility of photodiodes (PDs) on Si in the long-wavelength region, InAlAs/InGaAs metal-semiconductor-metal PDs were fabricated on high-quality heteroepitaxial InP layers on Si substrates. A dark current of 0.5–2×10−8 A and a responsivity of 0.05–0.15 A/W were reproducibly obtained, at least at one of the ±5 V bias voltages. These dark currents and responsivity are similar to those of PDs with the same structure fabricated on InP substrates. The PDs on Si have pulse responses with full widths at half-maximum of 150–600 ps.