Lateral n–p–n avalanche photodiode with an AlInAs multiplication layer

Abstract

A quasi-planar AlInAs avalanche photodiode (APD) with a lateral n–p–n structure for optical fibre communications is reported. Although both the anode and the cathode contact the n-type regions, it is demonstrated that the n–p–n APD has the same performance as a normal p–n APD. The n–p–n structure enables the p-type conversion process of thermal Zn diffusion to be omitted, and AlInAs with a large gain bandwidth product and low noise to be utilised for a multiplication region. The n–p–n AlInAs APDs can provide better receiver sensitivity at 10 Gbit/s than commercially available InP APDs.