Numerical modeling of electromagnetic resonance enhanced silicon metal-semiconductor-metal photodetectors.
A rigorous method of modeling the performance of metal-semiconductor-metal photodetectors (MSM-PD) that use several electromagnetic resonance (ER) modes and optical modes to enhance performance is presented. These ER and optical modes include surface plasmons, Wood-Rayleigh anomalies and vertical cavity modes. Five modeling algorithms are integrated together in a time-dependent way to model a 256 pseudo-random bit sequence (PRBS) of 850nm wavelength TM polarized light, the electromagnetic field distribution in the MSM-PD, quasi-static electric field, the charge carrier motion, and an algorithm to construct eye diagrams and analyze responsivity, inter-symbol interference (ISI) and bit error ratio (BER). We report on the use of a combination of ER and optical modes in channeling more than 83% of the incident light into the silicon even though 60% of the Si surface area is covered with metal contacts. Also, this channeled light is localized near the Si surface below the contact window. The absorption in the metal contacts, reflection, diffraction, electromagnetic field profiles, Poynting vector, photocurrent, eye diagrams, quality factors, responsivity and BER are calculated. Designs for Si MSM-PDs with a bandwidth of 100Gb/s, responsivities in the range of 0.05?0.30A/W and BERs in the range of 10-20?10-10 are described.