Publication

We report the first heterogeneous integration of a lithium niobate (LN) micro-ring modulator (MRM) on a silicon photonics platform using a high-precision, back-end-of-line (BEOL)-compatible micro-transfer printing (MTP) technique. Fully fabricated, low-loss LN devices are deterministically aligned and transfer-printed onto CMOS-compatible silicon photonic chips with sub-150 nm placement accuracy and high yield. The resulting hybrid MRM demonstrates an ultra-low insertion loss (<0.6 dB) and a low half-wave voltage–length product (VπL = 1.5 V·cm), achieved through optimized optical waveguide and electrode engineering. The integration scheme supports both lateral (in-plane) and vertical stacking configurations on silicon waveguides, providing versatile integration architectures. Array-level transfer onto foundry-fabricated silicon chips with completed redistribution layer (RDL) interconnects validates the scalability and BEOL compatibility of the process. This non-invasive integration approach addresses critical limitations of conventional LN-on-Si techniques and establishes a viable pathway toward monolithic integration of high-speed photonic I/Os for next-generation optical interconnect systems.

Researcher/Author: 

Yang Jie, Yan Ao

Conference Name : IEEE International Electron Devices Meeting 2025

Location : San Francisco, USA

Date : 6-10 December 2025