2024/07/12 by Zizheng Li, Li, Zizheng, Naresh Sharma +15 · 2 citations
Engineering · Materials Science · Physics and Astronomy · #Applied Physics (physics.app-ph) #FOS: Physical sciences #Ferroelectric and Piezoelectric Materials #Optics (physics.optics) #Photonic and Optical Devices #Photorefractive and Nonlinear Optics
paper · pdf · doi:10.48550/arxiv.2407.09350
openalex publication_date 2024/07/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In the past decade, lithium niobate (LiNbO3 or LN) photonics, thanks to its heat-free and fast electro-optical modulation, second-order non-linearities and low loss, has been extensively investigated. Despite numerous demonstrations of high-performance LN photonics, processing lithium niobate remains challenging and suffers from incompatibilities with standard complementary metal-oxide semiconductor (CMOS) fabrication lines, limiting its scalability. Silicon carbide (SiC) is an emerging material platform with a high refractive index, a large non-linear Kerr coefficient, and a promising candidate for heterogeneous integration with LN photonics. Current approaches of SiC/LN integration require transfer-bonding techniques, which are time-consuming, expensive, and lack precision in layer thickness. Here we show that amorphous silicon carbide (a-SiC), deposited using inductively coupled plasma enhanced chemical vapor deposition (ICPCVD) at low temperatures (< 165 C), can be conveniently integrated with LiNbO3 and processed to form high-performance photonics. Most importantly, the fabrication only involves a standard, silicon-compatible, reactive ion etching step and leaves the LiNbO3 intact, hence its compatibility with standard foundry processes. As a proof-of-principle, we fabricated waveguides and ring resonators on the developed a-SiC/LN platform and achieved intrinsic quality factors higher than 106,000 and resonance electro-optic tunability of 3.4 pm/V with 3 mm tuning length. We showcase the possibility of dense integration by fabricating and testing ring resonators with 40um radius without a noticeable loss penalty. Our platform offers a CMOS-compatible and scalable approach for implementation of future fast electro-optic modulators and reconfigurable photonic circuits as well as nonlinear processes which can benefit from involving both second and third-order nonlinearities.