InGaAsP/InP photodiodes: Microplasma-limited avalanche multiplication at 1-1.3-µm wavelength

Photodiodes for use in the
1-1.3-\mu
m wavelength region have been fabricated from double-heterostructure InGaAsP/InP wafers grown by liquid-phase epitaxy (LPE). The measured avalanche multiplication in mesa-configuration devices was limited to values of 10 or less. The results of careful measurement of the photoresponse, quantum efficiency, and reverse-bias
I-V
characteristics suggest that the gain is limited by microplasma breakdown. The density of microplasmas was estimated to be about 10
⁶
cm
^-2
, approximately equal to the etch pit density of the InP substrates used in growth of the epitaxial layers.