High‐responsivity InGaAs/InP‐based MSM photodetector operating at 1.3‐μm wavelength

A high‐responsivity, low‐capacitance and high‐speed metal‐semiconductor‐metal photodetector (MSM‐PD) with layer structure In0.85Ga0.15P/InP/InGaAs/InP has been fabricated and characterized. For a 50 μm × 50 μm device with 2‐μm finger width and 2‐μm finger spacing we obtained a front illumination at 1.3‐μm wavelength responsivity of 0.71–0.73 A/W at 5‐V bias. To the best of our knowledge this is the highest front illumination responsivity for MSM‐PD. The mesa structure devices show a very low capacitance of less than 1 pF and a transient response bandwidth of 10 GHz at 3 dB. © 1996 John Wiley & Sons, Inc.