Optoelectronic co-optimization of high-performance dual-port Ge/Si lateral photodetector with side confinement trenches

Photodetectors, which convert optical signals into electrical signals, are critical components in integrated silicon photonic platforms. This paper introduces a high-performance Ge/Si lateral photodetector design with dual-port incidence and confinement trenches on both sides. Compared to one-port incidence, the dual-port design significantly improves the light field and the distribution of photogenerated carriers in the Ge region. The confinement trenches in the Si layer on both sides of the Ge focus light more effectively into the Ge region, enhancing absorption efficiency and boosting responsivity. Following optoelectronic co-optimization, the 64-PD array, fabricated through MPW service, demonstrates high performance: dark current below 3nA, O-band responsivity above 0.92A/W, and small-signal bandwidth over 34GHz at 3V bias. The large-signal eye diagram test achieves a rate above 36Gbps, limited by the 40Gbps test system. The PD array exhibits consistent performance, making it highly suitable for applications in optical interconnects and optical computing.