The Flexible Magnetic-Electronic Materials and Devices Group from the Ningbo Institute of Materials Technology and Engineering (NIMTE) of the Chinese Academy of Sciences (CAS) has proposed a hybrid transfer and epitaxy strategy, enabling the heterogeneous integration of single-crystal oxide spin Hall materials on silicon substrates for high-performance oxide-based spintronic devices.

The study was published in Advanced Functional Materials.

Due to the advantages of low-power consumption, nonvolatility, and ultra-fast operating capabilities, spintronic devices have emerged as a key direction for next-generation information technologies.

Single-crystal oxide spin Hall materials exhibit exceptional charge-spin conversion efficiency, thus have been regarded as promising candidate materials for developing low-power spintronic devices, i.e. spin-orbit torque (SOT) devices. However, the heterogeneous integration of such materials with silicon-based substrates remains challenging.

To address this issue, researchers at NIMTE developed an innovative strategy combining transfer technology with epitaxial deposition, thus integrating oxide spin Hall materials onto silicon. Using this method, single-crystal SrRuO₃ (SRO) films were integrated on silicon substrates, and corresponding SOT devices were prepared.

The SRO film showed a high spin Hall conductivity of 6.1×10⁴ ħ/2e S·m⁻¹, enabling magnetization switching with a low critical current density of 1.3×10¹⁰ A·m⁻² in the SOT devices. Additionally, multi-state magnetization switching characteristics were observed in the devices, thus could be applied to simulate biological synaptic and neuronal functions. An artificial neural network based on these devices achieved a superior accuracy rate of 88% in image recognition tasks.  

This study pioneers a novel integration method for silicon-based oxide electronics. The hybrid transfer and epitaxy strategy demonstrates broad applicability across diverse oxide material systems, advancing the development of high-performance silicon-based spintronic devices. It also shows promising potential in low-power electronics and neuromorphic computing applications.

The work was supported by the National Key R&D Program of China (Nos. 2024YFA1410200, 2019YFA0307800), the National Natural Science Foundation of China (Nos. 12174406, 11874367, U24A6001, 52127803, 52422112), the CAS Youth Innovation Promotion Association (No. YSBR-109), the Ningbo Key R&D Program (No. 2022Z094), and the Ningbo Young Doctor Innovation Program (No. 2023J411).

Heterogeneous integration of single-crystal SrRuO₃ films on silicon for spin-orbit torque devices with low-power consumption (Image by NIMTE)

Contact
LU Zengxing
Ningbo Institute of Materials Technology and Engineering
E-mail: luzengxing@nimte.ac.cn