Stress-Released Si3n4 Fabrication Process For Dispersion-Engineered Integrated Silicon Photonics

We develop a stress-released stoichiometric silicon nitride (Si3N4) fabrication process for dispersion-engineered integrated silicon photonics. To relax the high tensile stress of a thick Si3N4 film grown by low-pressure chemical vapor deposition (LPCVD) process, we grow the film in two steps and introduce a conventional dense stress-release pattern onto a similar to 400nm-thick Si3N4 film in between the two steps. Our pattern helps minimize crack formation by releasing the stress of the film along high-symmetry periodic modulation directions and helps stop cracks from propagating. We demonstrate a nearly crack-free similar to 830nm-thick Si(3)N(4 )film on a 4 '' silicon wafer. Our Si3N4 photonic platform enables dispersion-engineered, waveguide-coupled microring and microdisk resonators, with cavity sizes of up to a millimeter. Specifically, our 115 mu m-radius microring exhibits an intrinsic quality (Q)-factor of similar to 2.0x10(6) for the TM00 mode and our 575 mu m-radius microdisk demonstrates an intrinsic Q of similar to 4.0x10(6) for TM modes in 1550nm wavelengths. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement