Analysis of uni-traveling-carrier photodetectors (UTC-PDs) with dipole-doped interface

A uni-traveling-carrier photodetector (UTC-PD) with dipole-doped structure at the InGaAs/InP interface has been designed, fabricated and characterized. The device transit time delay and RC time delay was extracted using an equivalent circuit model. A transit time delay time less than 4.5 ps was obtained with a junction reverse bias lager than 4 V. The results suggest that the current-blocking at InGaAs/InP interface can be effectively suppressed by the dipole-doped interface.