100 GHz bandwidth ultra-thin germanium photodetectors with high responsivity on a 300 mm silicon photonics process

Germanium photodetectors (Ge-PDs) are key components in silicon photonics (SiPh) to enable high-speed optical communications for various application. Several works have been reported to improve the bandwidth, quantum efficiency and manufacturing process of Ge-PDs. However, a significant trade-off between bandwidth and responsivity remains a major challenge in developing high-performance Ge-PDs for large-scale silicon photonic integrated circuits. Here, by co-optimizing of chemical mechanical polishing (CMP) process and device structure, ultra-thin Ge-PDs with high 3-dB bandwidth has been achieved. The dimensions of Ge region and doping areas have also been optimized to attain high bandwidth-quantum efficiency product. Consequently, we demonstrate lateral-PIN Ge-PDs with high bandwidth of up to 100 GHz, 1.05 A/W responsivity at 1550 nm and