Novel CMOS-Compatible Plasmonic Pressure Sensor with Silicon-Insulator-Silicon Waveguide Configuration

Abstract

This thesis introduces a novel CMOS-compatible plasmonic optical pressure sensor featuring a Silicon-Insulator-Silicon waveguide configuration. The sensor design incorporates a Railtrack resonator coupled to a straight waveguide with gratings, further enhanced by embedding silicon nanorods into the resonator cavity. This sensor demonstrates a notable redshift in the transmission spectrum related to the deformation of the resonator structure under applied pressure. The proposed sensor exhibits an unprecedented pressure sensitivity of 51.075 nm/MPa, arguably the highest value reported to date for Metal-Insulator-Metal based pressure sensors. Moreover, this work represents a novel instance of employing CMOScompatible silicon for designing an optical pressure sensor, thereby bridging the gap between plasmonic optomechanical sensors and nanoelectronics, while circumventing the compatibility issues typically associated with metals in standard CMOS fabrication processes. While traditional metals suffer from limited tunability due to their inherent carrier concentration constraints, silicon offers a promising solution as its optical properties can be finely tuned by modifying the doping levels, addressing the challenge of optical tunability. The sensor’s versatility and impact across diverse domains are highlighted by its potential applications, including gas leakage detection, flow rate measurement, electronic skin sensing, and pressure sensors as refractive index sensors for early diagnosis of organ rejection post-transplantation.