Lateral photodetectors on semi-insulating InGaAs and InP

A new type of high-performance lateral PIN photodector has been formed by alloying p-type and n-type metallic contacts onto semi-insulating InGaAs or InP without a separate junction fabrication step. Low dark current (<1 nA), high external quantum efficiency (40% at λ=1.24 μm, without antireflection coating), and high speed (full width at half-maximum <50 ps) have been obtained with reverse bias of 10 V. These characteristics, plus the simplicity of fabrication and the planar lateral configuration, make these devices attractive for monolithic integration with field-effect transistors and for photodetector arrays.