Planar-structure InP/InGaAsP/InGaAs avalanche photodiodes withpreferential lateral extended guard ring for 1.0-1.6 μm wavelengthoptical communication use

A planar InP-based InGaAs heterostructure avalanche photodiode (APD) with a preferential lateral extended guard ring is proposed. Optimum design and device fabrication are described for the planar-structure APD using various-donor-concentration n-InP avalanche layers, separated from the light-absorbing InGaAs layer. High performance results are low dark current, high speed, low noise, and uniform avalanche gain without edge breakdown. The APD yielded a sensitivity as high as -37.4 dBm for a 2-Gb/s 1.57-μm wavelength return-to-zero sequence with 10^-9 bit error rate