A monolithic 1 x 10 array of InGaAsP/InP photodiodes with small dark current and uniform responsivities

We fabricated a monolithic 1 × 10 array of InGaAsP/InP double-heterostructure photodiodes by liquid-phase epitaxy, which has highly uniform characteristics in breakdown voltages and responsivities and whose deviations in an array are ±1 percent and ±6 percent, respectively. The dark current of the elemental photodiode at low bias voltage, which is attributed mainly to the generation-recombination process in the depletion layer, is smaller than that of the germanium avalanche photodiode by one order at room temperature. The elemental photodiodes in the array have high quantum efficiency of more than 60 percent with SiOxfilm for antireflection in a wavelength range of1.0-1.2 , fast response time shorter than 1 ns, and very high cutoff frequency of about 800 MHz with the load resistance of 50 Ω.