10 Gb/s monolithic integrated MSM-photodiode AlGaAs/GaAs-HEMT optoelectronic receiver

A photoreceiver based on a metal-semiconductor-metal (MSM) photodiode and AlGaAs/GaAs HEMTs is presented. The photoreceiver was fabricated using a 0.5- mu m recessed-gate process for double delta-doped quantum-well HEMTs. The following mean values for the enhancement and depletion HEMT parameters, respectively, have been obtained: threshold voltages of 0.1 and -0.5 V, transconductances of 500 and 390 mS/mm, source resistances of 0.7 and 0.6 Omega -mm, and transit frequencies of 35 and 30 GHz. This process includes photodiodes. A deep wet etch was used to deposit the photodiodes on an undoped GaAs buffer layer.