Plasmonic Nanoslit Enhanced Metal-Semiconductor-Metal Photodetectors

Abstract

Abstract:We computationally show that metallic nanoslitsintegrated on Germanium metalsemiconductor-metal photodetectors show absorption enhancement up to 8 for TM-polarization in the communications C-band due to interference of horizontal surface plasmons.OCIS codes: 040.5160; 130.0250; 250.5403 Semiconductor industry has continuously scaled down electronic devices, significantly improving device level performance; but the same is not true for the on-chip electrical interconnections. The high frequency nature of photonics make optical interconnects a natural candidate for high capacity information transfer medium, resulting in an avalanching interest in demonstrating efficient Ge-based optical detection closely integrated with Silicon and Silicon based waveguide technologies to realize integrated optoelectronics [1][2][3].It is desirable that the finger spacing and active layer thickness in metal-semiconductor-metal (MSM) photodetectors be reduced for high-speed operation while maintaining the efficiency of the device. Despite earlier reports in the literature on electromagnetic resonance modes in MSM structures [4,5], a complete study does not exist and there is a need for a thorough investigation of plasmonic gratings integrated with MSM photodetectors.For a proof-of-concept demonstration in the near infrared (NIR) photodetectors, we computationally studied Germanium based MSM photodetectors integrated with gold gratings as shown in Fig. 1. We computed the field