New approach to the frequency response analysis of an InGaAs avalanche photodiode

The frequency response of an avalanche photodiode has been calculated by solving the transport equations, taking the electric field profile into account. The relationship between the carrier concentration (Nb) in the multiplication layer and the frequency response has been obtained for the first time. This calculation has been carried out for a conventional In/sub 0.53/Ga/sub 0.47/As avalanche photodiode. The results explain well present experimental data. The saturation velocity of holes in InP is estimated to be 2*10/sup 6/ cm/s. The upper limitation of the gain-bandwidth product is estimated to be 140 GHz at Nb=2*10/sup 17/ cm/sup -3/.<
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