Development of Uni-Travelling-Carrier Photodiodes

We have fabricated and characterized InGaAsP/InP uni-travelling-carrier photodiodes (UTC-PDs). An UTC-PD layer structure in the material system InGaAlAs/InP was also designed and grown with in-house molecular beam epitaxy (MBE). Using standard III-V processing involving lithography, metallization and etching, diodes of different sizes have been fabricated. Time domain and eye-diagram measurements have been performed. Limitations in the measurement system were identified and compensated for when measuring the bandwidth. The resulting bandwidth is in agreement with the area dependent RC-limitation which was estimated using quasi-DC capacitance-voltage (C-V) measurements