Ultrathin Pt and Mo films on Al1–Sc N: an interface investigation

Ultrathin Pt and Mo films on Al1–Sc N: an interface investigation

Applied Surface Science

10.1016/j.apsusc.2023.157921

http://dx.doi.org/10.1016/j.apsusc.2023.157921

Yishui Ding, Xiangyu Hou, Tengyu Jin, Yanan Wang, Xu Lian, Yuan Liu, Yihe Wang, Sisheng Duan, Xiangrui Geng, Meng Wang, Jingyu Mao, Yuanyuan Zhang, Peirong Tang, Minghua Li, Huamao Lin, Yao Zhu, Siewlang Teo, Qiang Zhu, Ming Lin, Wei Chen

Electrical and Electronic Engineering

03 July 2023

Ding, Y., Hou, X., Jin, T., Wang, Y., Lian, X., Liu, Y., Wang, Y., Duan, S., Geng, X., Wang, M., Mao, J., Zhang, Y., Tang, P., Li, M., Lin, H., Zhu, Y., Teo, S., Zhu, Q., Lin, M., & Chen, W. (2023). Ultrathin Pt and Mo films on Al1–Sc N: an interface investigation. Applied Surface Science, 637, 157921. https://doi.org/10.1016/j.apsusc.2023.157921

Aluminum scandium nitride (Al1–xScxN) with attractive ferroelectric and piezoelectric properties is a promising material for next-generation device applications. However, the understanding of interface properties between integrated ultrathin metal electrodes and Al1-xScxN films is still limited, despite their significant impact on device performance. In the study, we investigated the growth mechanism and interfacial chemistry of ultrathin platinum (Pt) and molybdenum (Mo) films deposited on the high-crystalline Al1-xScxN (x = 0.2) surface. The chemical and electronic structure evolutions of the interface during the deposition process were probed by in-situ X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS). The structural properties of the interface were further characterized by cross-sectional transmission electron microscopy (TEM), X-ray diffraction spectroscopy (XRD), and atomic force microscopy (AFM). Our results reveal the formation of ionic Pt2+-N bonds at the Pt/Al1-xScxN interface, while Mo does not bond with the substrate. Furthermore, we identified electron transfer induces upward band-bending like effects on the Al1-xScxN surface upon both Pt and Mo interactions. Our work on the chemical and structural research of ultrathin metal electrodes and Al1–xScxN interfaces provides guidance towards designing high-performance micro-electromechanical (MEMS) devices.

Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)

This research / project is supported by the Science and Engineering Research Council of A*STAR - Ferroelectric Aluminum Scandium Nitride (Al1-xScxN) Thin Films and Devices for mm-Wave and Edge Computing
Grant Reference no. : A20G9b0135

This research / project is supported by the Ministry of Education - Academic Research Fund Tier 2
Grant Reference no. : MOE-T2EP50220-0001

This research / project is supported by the National Research Foundation - National Research Foundation Investigatorship
Grant Reference no. : NRF-NRFI08-2022-0009

https://oar.a-star.edu.sg/communities-collections/articles/21151

0169-4332

Institute of Microelectronics