Residual defect center in GaInAs/InP films grown by molecular beam epitaxy

Schottky contact with apparent barrier height of near 0.65 eV has been fabricated and used to perform capacitance-voltage and deep level transient spectroscopy characterizations on n-type molecular beam epitaxy grown GaInAs layers matched to InP substrates. The experimental results show the existence of a residual defect center located at 0.33 eV below the conduction band which is here described for the first time. This defect center is localized close to the surface and the interface of the grown layers. The origin of the center is not clearly understood, but it seems to be a residual defect in which oxygen atom can be involved.