Design and simulation of an integrated waveguide and sensor: Towards a complete optoelectronic circuit on silicon

Nowadays, there is a need to integrate in a single silicon chip all the components to have an integrated optoelectronic circuit. In this paper, a design and computational simulation that demonstrate that feasibility of coupling a rib type optical waveguide with a photodiode on silicon substrate is carried out. The final goal is to have an integrated silicon circuit with a light source, an optical waveguide and a photodiode self-aligned. Also, details on the design and simulation of the sensor and some proposals of the fabrication process to integrate them are presented. The proposed optical waveguide is a rib type that uses silicon nitride as core and it is able to propagate an optical signal between 400 to 800 nm. The design and simulation of the photodiode considers two different topologies, position of the optical waveguide and different substrate resistivity. A transversal photodiode relative to the waveguide end appears the best configuration.