Monolithically integrated long wavelength photoreceiver OEIC based on InP/InGaAs HBT technology

Abstract

The epitaxial structure and growth, circuit design, fabrication process and characterization are described for the photoreceiver opto-electronic integrated circuit (OEIC) based on the InP/InGaAs HBT/PIN photodetector integration scheme. A 1.55 μm wavelength monolithically integrated photoreceiver OEIC is demonstrated with self-aligned InP/InGaAs heterojunction bipolar transistor (HBT) process. The InP/InGaAs HBT with a 2 μm × 8 μm emitter showed a DC gain of 40, a DC gain cutoff frequency of 45 GHz and a maximum frequency of oscillation of 54 GHz. The integrated InGaAs photodetector exhibited a responsivity of 0.45 A/W at λ = 1.55 μm, a dark current less than 10 nA at a bias of −5 V and a −3 dB bandwidth of 10.6 GHz. Clear and opening eye diagrams were obtained for an NRZ 223–1 pseudorandom code at both 2.5 and 3.0 Gbit/s. The sensitivity for a bit error ratio of 109 at 2.5 Gbit/s is less than −15.2 dBm.