Dislocation Evolvement in Metamorphic In0.83Ga0.17As/InP Photodetectors Through Ex-Situ Rapid Thermal Annealing

Ex-situ rapid thermal treatments of 1–2.5
$\mu \text{m}$
extended wavelength In
_0.83
Ga
_0.17
As/In
_0.83
Al
_0.17
As photodetector epiwafers on InP substrate were investigated. Enhanced photoluminescence intensities, narrower and stronger x-ray diffraction peaks, and decreased dislocation defect densities were observed with the increase of the rapid annealing temperature from 650°C to 750°C. Monotonically decreased dark current, dark noise and climbed peak detectivity for the photodetectors were attained. The cut-off wavelength remain unchanged after thermal treatments. The crystal lattice was irreversibly damaged and the device failed once the temperature was risens to 800°C. These results indicate that the ex-situ thermal treatment can serve as an effectively route to improve the qualities of metamorphic In
_x
Ga
_1−x
As materials as well as devices.