High speed 1.3 μm InGaAs/GaAs superlattice on Si photodetector

High speed metal-semiconductor-metal photodetectors sensitive at 1.3 μm have been realised on Si substrates. The active layer consists of a strained InGaAs/GaAs superlattice grown by molecular beam epitaxy on GaAs-on-Si. The device exhibits a very fast response at 1.3 μm (FWHM < 35 ps), a reasonable low dark current (2 μA and 8 μA at 10 and 20 V bias, respectively) and a wavelength dependent internal quantum efficiency of 15–50% at 20 V bias.