Performance analysis of an electrostatic doping assisted silicon microring modulator

In this paper, we propose and numerically analyze electrostatic doping (ED) assisted silicon microring modulator (MRM) realizable on SOI platform having ∼10nm free spectral range (FSR). The proposed modulator consists of a vertical metal-insulator-semiconductor (MIS) junction and a lateral metal-semiconductor (MS) junction. It utilizes ED to achieve free carriers inside the rib waveguide that eventually introduces the free carrier plasma dispersion effect. The proposed device does not employ any lateral or vertical PN or PIN junction and offers high operating speed with negligible static power consumption. Numerical simulation using commercially available TCAD tools and mode solvers are used to estimate the performance of the proposed modulators. Palladium (Pd) and aluminum (Al) are used as electrodes to realize ED enabled MIS-MS charge plasma diode. The performance of the proposed modulator is extensively studied both in steady state and transient state. Results predict that a maximum 37.8 dB and 33 dB of extinction ratio (ER) is achievable by the modulator while operating in inversion and accumulation mode, respectively. Predicted insertion losses are 1.97 dB and 1.49 dB when operated in inversion and accumulation mode respectively. The proposed modulator is expected to provide a maximum of 26.3 Gbps and 32.2 Gbps operating speed with a 9.21 GHz and 11.29 GHz of 3-dB optical bandwidth in inversion and accumulation mode of operation, respectively. Simulation result predicts that the dynamic energy per bit for the proposed ED assisted MRM is approximately 31 fJ/bit and 68 fJ/bit in inversion and accumulation mode of operation, respectively.