Performance of In0.53Ga0.47As/InP avalanche photodiodes

We calculate operating characteristics of high-sensitivity high-speed In
0.53
Ga
0.47
As/InP avalanche photodiodes (APD's). We find that significant photocurrent gain is obtained for a total fixed-charge density of
\sigma_{tot} > 3 \times 10^{12}
cm
^-2
in the depleted InP and
0.53
Ga
0.47
As regions. To obtain high quantum efficiency and low tunneling currents, the fixed-charge density in the InP must be in the range
2 \times 10^{12}
cm
^-2
\leq \sigma_{B} \leq 3 \times 10^{12}
cm
^-2
. We calculate the breakdown voltages for APD's with uniformly doped layers and find that practical detectors with avalanche breakdowns as low as 15 V can be realized. High quantum efficiency and fast response are obtained by compositional grading of the In
0.53
Ga
0.47
As heterointerface over a distance of
L \gsim 380
Å, depending on the doping and amount of the In
0.53
Ga
0.47
As layer swept out at breakdown. Finally, a comparison of calculations with experimental results is presented.