Biaxial Texture Evolution in MgO Films Fabricated Using Ion Beam-Assisted Deposition

• Published in: Journal of electronic materials 2016-07, Vol.45 (7), p.3546-3553
• Main Authors: Xue, Yan, Zhang, Ya-Hui, Zhao, Rui-Peng, Zhang, Fei, Lu, Yu-Ming, Cai, Chuan-Bing, Xiong, Jie, Tao, Bo-Wan
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemical compounds; Chemistry and Materials Science; Electronics; Electronics and Microelectronics; Instrumentation; Materials Science; Optical and Electronic Materials; Solid State Physics; Thin films
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-016-4514-5

The growth of multifunctional thin films on flexible substrates is important technologically, because flexible electronics require such a platform. In this study, we examined the evolution of biaxial texture in MgO films prepared using ion beam-assisted deposition (IBAD) on a Hastelloy substrate. Texture and microstructure developments were characterized through in situ reflection high-energy electron diffraction monitoring, x-ray diffraction, and atomic force microscopy, which demonstrated that biaxial texture was developed during the nucleation stage (~2.2 nm). The best biaxial texture was obtained with a thickness of approximately 12 nm. As MgO continued to grow, the influence of surface energy was reduced, and film growth was driven by the attempt to minimize volume free-energy density. Thus the MgO grains were subsequently rotated at the (002) direction toward the ion beam. In addition, an approach was developed for accelerating in-plane texture evolution by pre-depositing an amorphous MgO layer before IBAD.