Vapor phase epitaxially grown InGaAs photodiodes

Vapor phase In
x
Ga
1-x
As photodiodes were fabricated for compositions
x = 0-0.57
. p
⁺
-layers were made by Zn diffusion using ZnAs
2
as a Source. Dark currents at half the breakdown voltage for
x
= 0.15, 0.17, and 0.31 were as low as those fabricated by liquid phase epitaxy. The planar structure is superior to a mesa structure with respect to dark current. Dark currents for various compositions were compared with theoretical estimation. Current multiplications in planar diodes with
x = 0.31
were about 10 at the junction center and 200-300 at the periphery. Response time to 1.06-µm Nd: YAG mode locked laser pulses was measured to be about 250 ps.