Microring and microdisk optical resonators using silicon nanocrystals and erbium prepared using silicon technology

A methodology for the integration of narrow-linewidth light sources monolithically onto silicon using silicon process technology is presented. Microcavity resonator based narrow-linewidth light sources were designed and modeled using the 3-D full-wave finite-difference time-domain (FDTD) method of solving Maxwell's equations. The microcavity confines light to a small modal volume by resonant recirculation in a structure with low roundtrip optical loss. The resonators were formed in close proximity to waveguides used for evanescent-wave coupling of light out of the microcavity. Waveguides using Si-nanocrystals in SiO2 are difficult to couple to planar microdisks because the mode extends deep into the oxide, whereas simulations show that microresonators using SiNx can. The coupling efficiency between the resonator and the single-mode waveguides was optimized by varying the gap size and the waveguide width and thickness. Luminescence from silicon nanoparticles in both SiO2 and SiNx films was studied. Process optimization for forming Si nanoparticles in SiO2 or SiNx including the effects of hydrogen annealing and the preparation of SiNx films with excess Si by various techniques (CVD and Si ion implantation) was performed. High-index-contrast microcavity resonators were fabricated using SiNx on SiO2 with silicon nanoparticles and imaged using atomic force microscopy. The structures include microdisk and microring cavities doped with silicon nanoparticles with and without erbium.