Structural characterization of the abnormal grains evolution in sputtered ScAlN films

Structural characterization of the abnormal grains evolution in sputtered ScAlN films

2021 IEEE International Ultrasonics Symposium (IUS)

10.1109/IUS52206.2021.9593514

http://dx.doi.org/10.1109/ius52206.2021.9593514

Minghua Li, Kan Hu, Huamao Lin, Yao Zhu

13 November 2021

Li, M., Hu, K., Lin, H., & Zhu, Y. (2021). Structural characterization of the abnormal grains evolution in sputtered ScAlN films. 2021 IEEE International Ultrasonics Symposium (IUS). https://doi.org/10.1109/ius52206.2021.9593514

The mis-oriented abnormal grains embedded in the sputtered scandium aluminum nitride (ScAlN) film degrade the film piezoelectric response. In this paper, we present for the first time the in-plane TEM observation of the crystal grains morphology and the microstructure of the sputtered Sc 0.2 Al 0.8 N film. The columnar normal grains are highly (0002) textured and exhibit the hexagonal cross-section morphology with six well-developed {1011} side facets. The abnormal grains show irregular cross-section. The grain boundary study reveals that the abnormal grains grow laterally and consume their neighboring normal grains during the film sputtering.

Publisher Copyright

This research / project is supported by the A*STAR - Programmatic - Ferroelectric Aluminum Scandium Nitride (Al1-xScxN) Thin Films and Devices for mm-Wave and Edge Computing (WP5)
Grant Reference no. : A20G9b0135

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Institute of Microelectronics