High Speed ($\boldsymbol{f}_{3-\boldsymbol{d}\boldsymbol{B}}$ above 10 GHz) Photo Detection at Two-micron-wavelength Realized by GeSn/Ge Multiple-quantum-well Photodiode on a 300 mm Si Substrate

High speed photo detection at two-micron-wavelength has been achieved with a GeSn/Ge multiple-quantum-well (MQW) photodiode (PD), demonstrating a 3-dB bandwidth $(f_{3-dB})$ above 10 GHz for the first time. The device layer stack was grown on a standard 300 mm (001) Si substrate using RPCVD, showing potential for large-scale integration. Radio frequency (RF) characterization was performed using $2- \mu\mathrm{m}$ RF optical measurement setup. To our knowledge, this is also the first PDs on Si with direct RF measurement to quantitatively confirm the high speed functionality at $2\ \mu \mathrm{m}$.