Theoretical and experimental studies of monolithically integrated pseudomorphic InGaAs/AlGaAs MODFET-APD photoreceivers

A detailed theoretical analysis has been made of the frequency response and noise performance of the integrated device, taking account of the material characteristics of the pseudomorphic InGaAs/AlGaAs heterostructure and GaAs/AlGaAs multi-quantum-well (MQW) avalanche photodiode (APD). The effects of adding an inductor between the output on the detector and the input of the transistor and the effects of a feedback resistance on the noise, speed, and gain characteristics have been investigated. The authors have fabricated and measured the performance characteristics of a monolithic device consisting of an InGaAs/AlGaAs pseudomorphic single-quantum-well MODFET with 1- mu m gate length and a 30 mu m*50 mu m APD with a 13-period GaAs/AlGaAs (400/400 AA) avalanching region on top of it and isolated from the FET by an AlGaAs layer. The devices were coupled with monolithic resistors and inductors and with air-bridge technology. The entire structure was grown on GaAs substrates by MBE (molecular-beam epitaxy) and is believed to be the first demonstration of a pseudomorphic and MQW integrated device. The measured characteristics of the device are reported.<
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