MOCVD Growth of InGaAs Metamorphic Heterostructures for Photodiodes with Low Dark Current

The epitaxial growth technique of InGaAs photodiode structures based on a digital InGaAs/GaAs metamorphic buffer layer by metalorganic chemical vapor deposition has been developed. The spectral dependence of the photocurrent of photodiodes based on the produced structures has a maximum at the 1.24 μm wavelength. The photosensitivity range at 10% of peak is 1.17–1.29 μm at room temperature. The current-voltage characteristics in the temperature range 9–300 K were investigated. It is shown that the dark current consists of generation-recombination and tunneling components. The dark current density at room temperature was 8 × 10 –5 A/cm 2 with a reverse bias of –5 V.