Fig. 3: Material and device characterization and geometries for thin and thick nitride anneal-free devices.
From: Anneal-free ultra-low loss silicon nitride integrated photonics
a SiN X-ray photoelectron spectroscopy (XPS) measurement showing a Si:N ratio of about 0.89:1. b Thin nitride waveguide geometry. c Thin nitride chip showing ring resonators, ring-bus coupling, and other test structures. d Top-down Scanning Electron Microscopy (SEM) image of the thin nitride waveguide with a width of 6 μm and gap of 3.5 μm on the mask. Measured gap is 3.44 μm, and waveguide widths are 6.01 and 5.96 μm, respectively. e Thick nitride waveguide geometry. f A thick nitride chip showing a bend loss spiral, ring-bus coupling, and other test structures. g Top-down SEM image of an 800 nm-thick nitride waveguide ring resonator, with a waveguide width of 1.4 μm and gap of 400 nm on the mask. The measured gap is 0.44 μm, and the measured waveguide widths are 1.32 and 1.27 μm, respectively. This confirms the high quality of our thick nitride waveguides
