Dense Periodical Patterns In Photonic Devices: Technology For Fabrication And Device Performance

DENSE PERIODICAL PATTERNS IN PHOTONIC DEVICES:TECHNOLOGY FOR FABRICATION AND DEVICE PERFORMANCEbySABARISH CHANDRAMOHANDecember 2016 Advisor: Dr. Ivan AvrutskyMajor: Electrical EngineeringDegree: Doctor of Philosophy For the fabrication, focused ion beam parameters are investigated to successfullyfabricate dense periodical patterns, such as gratings, on hard transition metal nitride such aszirconium nitride. Transition metal nitrides such as titanium nitride and zirconium nitride haverecently been studied as alternative materials for plasmonic devices because of its plasmonicresonance in the visible and near-infrared ranges, material strength, CMOS compatibility, andoptical properties resembling gold. Coupling of light on the surface of these materials using sub-micrometer gratings gives additional capabilities for wider applications. Here we report thefabrication of gratings on the surface of zirconium nitride using gallium ion 30keV dual beamfocused ion beam. Scanning electron microscope imaging and atomic force microscope profiling is used to characterize the fabricated gratings. Appropriate values for FIB parameters such as ionbeam current, magnification, dwell time, and milling rate are found for successful milling ofdense patterns on zirconium nitride.For the device performance, a real-time image-processing algorithm is developed toenhance the sensitivity of an optical miniature spectrometer. The novel approach in this design is