Compact biosensors based on thin film silicon nitride microring resonators

Abstract

Abstract We presented a silicon microring resonator based on thin film silicon nitride waveguide for biosensor applications. Design and fabrication were conducted. The device was fabricated on a silicon nitride wafer with 250 nm top film on 3 μm buried oxide by using electron-beam lithography and inductively coupled plasma etching. The radius of the microring is as smaller as 50 μm. The quality factor of the resonator is 8610. The spectra and resonance shift for bulk sensing were measured by flowing sodium chloride solutions with different concentrations on the surface of the sensor. The sensitivity and the LOD of the sensor are 384.58 nm/RIU and 4.68×10−4 RIU, respectively.