High-Speed InGaAs P-I-N Photodetector With Planar Buried Heterostructure

An InGaAs buried-heterostructure photodetector (BH-PD) was proposed and fabricated. By introducing etching and refilling with large bandgap and lower concentration semi-insulating InP, it was found that we can reduce the capacitance of P-I-N PDs by 33% without significantly increasing the reverse leakage current. It was also found that we can achieve a 3-dB bandwidth of 11.8 GHz from BH-PD, which was much larger than the 7.1-GHz 3-dB bandwidth observed from conventional InGaAs P-I-N PDs.