Fully complementary metal-oxide-semiconductor compatible nanoplasmonic slot waveguides for silicon electronic photonic integrated circuits

Horizontal Al/SiO2/Si/SiO2/Al nanoplasmonic slot waveguides with the SiO2 width at each side of similar to 15 nm and the Si core width of similar to 136-43 nm were fabricated using a fully silicon complementary metal-oxide-semiconductor compatible technology. The propagation losses were measured to be similar to 1.07-1.63 dB/mu m at the telecommunication wavelength of 1550 nm, in agreement with those predicted from numerical simulation. A simple tapered coupler with length of similar to 0.3-1 mu m provides a high coupling efficiency of similar to-0.6--1.5 dB between the plasmonic waveguide and the conventional Si dielectric waveguide. The plasmonic slot waveguide can achieve a low-loss ultracompact bend. A direct 90 degrees bend was demonstrated to have the pure bending loss as low as similar to 0.2-0.4 dB. The losses of propagation, coupling, and bending depend weakly on wavelength in the c-band. These results demonstrate the potential for seamless integration of functional plasmonic devices in existing silicon electronic photonic integrated circuits. (C) 2011 American Institute of Physics. [doi:10.1063/1.3537964]