Abstract

High-Q Si₃N₄ microresonators are the central elements for Kerr nonlinear photonics, with applications in optical communication [1], ultrafast ranging [2], spectroscopy [3], etc. These applications usually require operation in the anomalous dispersion regime with waveguide thickness exceeding 600 nm, yet cracks may occur in such thick films during fabrication [4]. Methods such as two-time deposition and annealing are applied to release the large stress in Si₃N₄ film [5] [6], introducing unnecessary complexity. To date, the lowest loss Si₃N₄ PICs require electron-beam (e-beam) lithography and are not wafer scale. Here we present a wafer-scale fabrication process for ultra-low loss, high confinement Si₃N₄ PICs, featuring only one deposition step for the Si₃N₄ film.

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