Punch-through type InGaAs photodetector fabricated by vapor-phase epitaxy

Punch-throughact-Punch-throught ype InGaAs/InPp hotodiodes were made from high purity layers grown on (100) InP substrates by vapor-phase epitaxy. High-speed photoresponse to a mode-locked Nd:YAG laser was observed owing to as low carrier concentration as 1 X 10
¹⁵
cm
^-3
Full width at half maximum and rise time of the pulse response were 126 and 82 ps, respectively, at above 4 V. Dark current was affected by substrate etch pit densities and was 4.1 X 10
^-4
A/cm
²
at 0.5 V
_B
for a diode made from the layer on dislocation free substrate. A uniform photocurrent multiplication factor of 5 was obtained.