Foundry manufacturing of tight-confinement, dispersion-engineered, ultralow-loss silicon nitride photonic integrated circuit

Abstract

The foundry development of integrated photonics has revolutionized today's optical interconnect and datacenters. Over the last decade, we have witnessed the rising of silicon nitride (Si${}_3$N${}_4$) integrated photonics, which is currently transferring from laboratory research to foundry manufacturing. The development and transition are triggered by the ultimate need of low optical loss offered by Si${}_3$N${}_4$, which is beyond the reach of silicon and III-V semiconductors. Combined with modest Kerr nonlinearity, tight optical confinement and dispersion engineering, Si${}_3$N${}_4$ has today become the leading platform for linear and Kerr nonlinear photonics, and has enabled chip-scale lasers featuring ultralow noise on par with table-top fiber lasers. However, so far all the reported fabrication processes of tight-confinement, dispersion-engineered Si${}_3$N${}_4$ photonic integrated circuit (PIC) with optical loss down to few dB/m have only been developed on 4-inch or smaller wafers. Yet, to transfer these processes to established CMOS foundries that typically operate 6-inch or even larger wafers, challenges remain. In this work, we demonstrate the first foundry-standard fabrication process of Si${}_3$N${}_4$ PIC with only 2.6 dB/m loss, thickness above 800 nm, and near 100% fabrication yield on 6-inch wafers. Such thick and ultralow-loss Si${}_3$N${}_4$ PIC enables low-threshold generation of soliton frequency combs. Merging with advanced heterogeneous integration, active ultralow-loss Si${}_3$N${}_4$ integrated photonics could pave an avenue to addressing future demands in our increasingly information-driven society.

References in corpus (12)

• All-optical signal processing platforms for CMOS compatible integrated nonlinear optics
• Photonics for artificial intelligence and neuromorphic computing
• Integrated Photonic Quantum Technologies
• Integrated micro-comb sources for quantum optical applications
• Stably accessing octave-spanning microresonator frequency combs in the soliton regime
• Bringing short-lived dissipative Kerr soliton states in microresonators into a steady state
• High-Q Si3N4 microresonators based on a subtractive processing for Kerr nonlinear optics
• Exploiting Ultralow Loss Multimode Waveguides for Broadband Frequency Combs
• Strong polarization mode coupling in microresonators
• Dissipative Kerr soliton microcombs for FEC-free optical communications over 100 channels
• Thermal control of Kerr microresonator soliton comb via an optical sideband
• Soliton pulse pairs at multiple colors in normal dispersion microresonators