CMOS-compatible MIS–Schottky heterojunctions for plasmonic waveguide modulation

A silicon-integrated Schottky metal-insulator-semiconductor plasmonic modulator with remarkable optical loss performance is demonstrated. The proposed device architecture is realized through the heterogeneous integration of amorphous aluminum, silica, and indium tin oxide, forming a metal-insulator-semiconductor plasmonic stack housed on an SOI substrate. The device exhibited extinction ratio and insertion loss levels of 1 dB/μm and 0.128 dB/μm, respectively for a 10 μm-long waveguide. By taking advantage of the absence of diffraction limits in plasmonic structures, strong modal confinement proved possible as evidenced by simulation results, paving the way for improved optical processes and miniaturized photonic circuits.