Fast, low-noise and sensitive avalanche photoreceivers are needed for surging short-reach photonic applications. Limitations concerning bandwidth, throughput and energy consumption should be overcome. In this work, we comprehensively study the performance opportunities provided by avalanche p-i-n photodetectors with lateral silicongermanium-silicon heterojunctions. Our aim is to circumvent the need for chip-bonded electronic amplifiers. In particular, we demonstrate that avalanche photodetectors based on silicongermanium-silicon heterostructures yield reliable opto-electrical performances, with high gain-bandwidth products up to 480 GHz and low effective ionization ratios down to 0.15. Moreover, they improve power sensitivities for high-speed optical signals and have a low energy dissipation of only a few fJ per received information bit. These results pave the way for high-performing receivers for energy-aware data links, in next-generation shortdistance data communications.
IndexTerms-Group-IV semiconductors; Integrated photonics; Avalanche photodetectors; Energy consumption; Short-reach communications; CMOS technology
I. INTRODUCTIONHE relentless demands of data-hungry devices as in data centers [1], high-performance computers and servers [2] or big data clouds and storages [3] places exponential requirements on electrical wire signaling. Data overflow in metal wires is a critical bottleneck that hampers the take-off of such devices. The benefits of optical interconnects extend from long-distance to short-distance systems. Components used in long-haul systems are too costly and complex to be adopted in short-reach systems, however. Short-reach architectures comprise opto-electrical and electro-optical Manuscript received MAY 31, 2021.