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 $\mu$m wavelength. The photosensitivity range at 10% of peak is 1.17–1.29 $\mu$m 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 $\cdot$ 10$^{-5}$ A/cm$^2$ with a reverse bias of -5 V.