Indium phosphide-based high performance quantum well avalanche photodiodes and integrated photoreceivers.

Large bandwidth optical communication systems are becoming more important than ever for transferring information efficiently. The availability of high performance photodetectors and front-end photoreceivers that operate in the low-loss 1.55 $\mu$m wavelength window of silica optical fibers is crucial for the development of these systems. The objective of the present work was to design, fabricate, and characterize InP-based discrete Separate Absorption and Multiplication Avalanche Photodiodes with a strained MQW avalanche region (SAM(MQW)-APD) and monolithically integrated transimpedance PIN-FET and PIN-HBT photoreceivers, which operate at multi-Gbit/s. High-speed and high gain-bandwidth product SAM(MQW)-APDs with a strained In$\sb{x}$Ga$\sb{1-x}$As/In$\sb{y}$Al$\sb{1-y}$As avalanche region were fabricated and characterized. An APD using hole injection into a lattice-matched MQW multiplication region demonstrated a bandwidth of $\sim$6.7 GHz, while an APD with tensile strain in the wells and compressive strain in the barriers demonstrated a bandwidth of $\sim$7.9 GHz. An APD using electron injection into a lattice-matched MQW multiplication region demonstrated a G*BW product of $\sim$110 GHz, while an APD with compressive strain in the wells and tensile strain in the barriers demonstrated a G*BW product of $\sim$139 GHz. Integrated PIN-FET photoreceivers with transimpedance and transimpedance/voltage amplifiers based on regrown 0.1 $\mu$m gate length MODFETs were fabricated and characterized. The regrown MODFETs demonstrated high transconductance, with peak values of 610 mS/mm and current densities up to 350 mA/mm at a drain bias of 1.5 V, and $f\sb{T}$ and $f\sb{max}$ of 104 GHz and 70 GHz, respectively. The photoreceiver with a 3-transistor transimpedance amplifier showed a transimpedance gain of 42 dB$\Omega$, and an optical-to-electrical conversion $-$3 dB bandwidth of 9.5 GHz. The photoreceiver with a 7-transistor transimpedance/voltage amplifier exhibited a transimpedance gain of 63 dB$\Omega$, and an optical-to-electrical bandwidth of 3.3 GHz. Integrated PIN-HBT transimpedance photoreceivers using the base, collector and subcollector HBT layers as the p-i-n photodiode were fabricated and characterized. Discrete HBTs demonstrated 54 GHz and 51 GHz for $f\sb{T}$ and $f\sb{max}$, respectively. The transimpedance amplifier exhibited an electrical transimpedance bandwidth of 17 GHz and 10 GHz with and without a peaking inductor, and a gain of 40 dB$\Omega$. The integrated photoreceiver with a 10 $\mu$m x 10 $\mu$m p-i-n photodiode demonstrated an optical-to-electrical conversion $-$3 dB bandwidth of 7.1 GHz.