Manufacturable 2.5 Gbit/s edge-coupled waveguide photodiode for optical hybrid-integrated modules

Side-illuminated photodiodes designed for surface hybrid integration on a silicon optical bench are described. InGaAs PIN photodiode chips fabricated on a 2inch-wafer with an integrated dry etched waveguide input facet with an antireflection coating deposition on the wafer, exhibit very low dark currents of typically 20 pA at -10 V bias voltage and 25°C. Fiber coupled responsivity as high as 0.95 A/W at 1.3 μm wavelength, and vertical coupling tolerance at -1 dB as wide as ±2 μm are demonstrated. Reliability testing under high temperature and bias-stress conditions shows very stable operation.