Highly Sensitive Wavelength-scale Amorphous Hybrid Plasmonic Detectors

Abstract

Hybrid integration of plasmonics and Si photonics is a promising architecture for global microprocessor interconnects. To this end, practical plasmonic devices not only should provide athermal, broadband operation over wavelength-scale footprint, but also support non-intrusive integration with low-loss Si waveguides as well as CMOS back-end-of-line processes. Here, we demonstrate a hybrid plasmonic photodetector with a single active junction fabricated via back-end deposited amorphous materials coupled to Si nanowires with only 1.5dB loss. Utilizing internal photoemission, our detectors measured sensitivity of -35dBm in a 620nm by 5{\mu}m footprint at 7V bias. Moreover, responsivity up to 0.4mA/W and dark current down to 0.2nA were obtained. The high process tolerance is demonstrated between {\lambda}=1.2-1.8{\mu}m and up to 100{\deg}C. The results suggest the potential towards plasmonic-photonic optoelectronic integration on top of Si chips without costly process modifications.