Characterization of InGaAs/InAlAs Separate Absorption and Multiplication Layers (SAM) Avalanche Photodiodes (APD) for Geiger Mode Operation

InGaAs/InAlAs SAM APDs are characterized with the purpose of using these devices as single photon avalanche diodes (SPAD). Typical gains for these devices in linear mode are shown to approach 40. Sidewall leakage, due to the exposed mesa structure of the device, is limited with the application of a dielectric, and shown to be insignificant. Dark current, with respect to bias at a gain of 10, was shown to be below 1nA when cooled below 273K, and thus would be well suited for Geiger mode operation.