Optical properties of scandium-doped aluminum nitride thin film for integrated photonics

Optical properties of scandium-doped aluminum nitride thin film for integrated photonics

Integrated Optics: Devices, Materials, and Technologies XXIX

10.1117/12.3042068

https://doi.org/10.1117/12.3042068

Nanxi Li, Yangyang Zhuge, Wing Wai Chung, Xiangxin Gong, Siyu Xu, Yanmei Cao, Minghua Li, Yat Fung Tsang, Yeow Teck Toh, Steven Hou Jang Lee, Huamao Lin, Landobasa Y. Tobing, Chong Pei Ho, Sang Hoon Chae, Xianshu Luo, Chengkuo Lee

19 March 2025

Li, N., Zhuge, Y., Chung, W. W., Gong, X., Xu, S., Cao, Y., Li, M., Tsang, Y. F., Toh, Y. T., Lee, S. H. J., Lin, H., Tobing, L. Y., Ho, C. P., Chae, S. H., Luo, X., & Lee, C. (2025). Optical properties of scandium-doped aluminum nitride thin film for integrated photonics. In S. M. García-Blanco & P. Cheben (Editors), Integrated Optics: Devices, Materials, and Technologies XXIX. https://doi.org/10.1117/12.3042068

Scandium (Sc)-doped aluminum nitride (AlN) has been widely used as a piezoelectric material in Micro-Electromechanical Systems (MEMS) devices. Recently, it also draws interests in photonics research contributed by its enhanced nonlinear optical property. Here, we report the (n, k) values of Sc-doped AlN thin films under various doping concentrations. These thin films with thickness of around 500 nm are deposited on silica through co-sputtering process. Reduced optical bandgap energies are observed at higher Sc doping concentrations. Furthermore, the top surface roughness of < 1 nm has been obtained through atomic force microscopy (AFM) measurement for the 30% Sc-doped AlN film in a 1 × 1 μm^2 region. Also, with etching process optimization, the 10% Sc-doped photonic waveguide sidewall angle and roughness have been obtained as ⪆80° and ⪅ 5 nm, respectively. Additionally, the patterned microring cavity has been characterized, with estimated intrinsic Q of 5.54×10^4 . The reported results here pave the way towards Sc-doped AlN for integrated photonics, with potential applications in communication, sensing, and quantum computing.

Publisher Copyright

This research / project is supported by the Agency for Science, Technology and Research - Chip-scale Multispectral 3D Scanner (CMUS)
Grant Reference no. : M23M5a0069

This research / project is supported by the Agency for Science, Technology and Research - Lightning
Grant Reference no. : C220415015

This research / project is supported by the Agency for Science, Technology and Research - On-chip Mode-Locked Lasers using Heterogeneous Integration of Graphene for Scalable Manufacturing
Grant Reference no. : M23M6c0109

This research / project is supported by the Singapore Ministry of Education (MOE) - Academic Research Fund (AcRF) Tier 1
Grant Reference no. : Grants (RT2/23)

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https://oar.a-star.edu.sg/communities-collections/articles/23129

https://doi.org/10.1117/12.3042068

Institute of Microelectronics