Characteristics of Al$_{x}$In 1−$_{x}$As $_{y}$Sb1− $_{y}$ (x:0.3−0.7) Avalanche Photodiodes

We report avalanche photodiodes fabricated from Al
_x
In
_1-x
As
_y
Sb
_1-y
wafers grown by molecular beam epitaxy using the digital alloy technique. A series of Al
_x
In
_1-x
As
_y
Sb
_1-y
(x = 0.3, 0.4, 0.5, 0.6, 0.7) p-i-n structures have been grown on GaSb substrate. Dark current, avalanche multiplication, excess noise, and external quantum efficiencies have been characterized. Very low excess noise, as characterized by k ~ 0.01-0.05, has been achieved.