Design and performance of InAlGaAs/InAlAs superlattice avalanche photodiodes

InAlGaAs-InAlAs superlattice avalanche photodiodes (SL-APD's) have been designed and experimentally analyzed. The layer structures and the electric field profiles were designed for 10 Gb/s applications. The mesa-structure SL-APD's exhibited a gain-bandwidth product of 120-150 GHz, a top bandwidth of 15 GHz, and a multiplied dark current of 15-20 nA for a mesa-diameter of 30 /spl mu/m. Other characteristics, such as temperature dependence of dark current and dynamic ranges, were also analyzed. Furthermore, an estimated life-time of longer than 10/sup 5/ h was achieved for the first time. The obtained characteristics, especially their high-speed characteristics with their low dark current, indicate potential for 2.5-10 Gb/s high-sensitivity and small optical receiver applications.