Electrical and Physical Properties of Sodium Potassium Niobates Thin Films Prepared by rf Magnetron Sputtering Technology

Abstract:

Lead-free potassium sodium niobate ceramic thin films were synthesized using rf magnetron sputtering technology for MFIS structures. The optimal sputtering parameters of the as-deposited KNN thin films for depositing times of 1h were obtained. Regarding the measured physical properties, the micro-structure and thickness of as-deposited KNN thin films for different oxygen concentration were obtained and compared by XRD patterns and SEM images. The surface roughness of KNN thin film was also observed by AFM morphology. The average grain size and root mean square roughness were 250 and 7.04 nm, respectively. For KNN thin films in the MFIS structure, the capacitance and leakage current density were 280 pF and 10^-8A/cm², respectively. We investigated that the leakage current density and the memory window increased, the capacitance critically increased as the oxygen concentration increased from 0 to 40%. However, the excess oxygen concentration process was decreased the electrical and physical of as-deposited KNN thin film. The effect of oxygen concentration on the physical and electrical characteristics of KNN thin films was investigated and determined.

• Periodical: Advanced Materials Research (Volumes 239-242)
• Pages: 532-535
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.239-242.532
• Online since: May 2011
• Authors: Chien Min Cheng, Shih Fang Chen, Jen Hwan Tsai, Kai Huang Chen, Hsiu Hsien Su
• Keywords: KNN Thin Film, Leakage Current Density, Memory Window, NvFeRAM, RF Sputtering

References

[1] I. G. Ismailzade, V. I. Nesterenko, Sov. Phys. Crystallogr. 12 (1968) 625.

[2] M. Kimura, T. Sawada, A. Ando, Y. Sakabe, Jpn, J. Appl. Phys. 38 (1998) 5557.

[3] J. F. Scott and C. A. Paz de Araujo, Science 246, 1400 (1989).

[4] D. J. Taylor, R. E. Jones, P. Zurcher, P. Chu, Y. T. Lii, B. Jiang, and S. J. Gillespie, Appl. Phys. Lett. 68, 2300 (1996).

[5] J. F. Scott and C. A. Paz de Araujo, Science 246, 1400 (1989).

[6] Y. Guo, K. Kakimoto, H. Ohsato, Appl. Phys. Lett. 85 (2004) 4121.

[7] M. Demartin Maeder, D. Damjanovic, and N. Setter, J. Eur. Ceram. Soc. 13 (2004) 385.

[8] Y. Saito, H. Takao, T. Tani, T. Nonoyama, K. Takatori, T. Homma, T. Nagaya. And M. Nakamura, Nature (London) 432 (2004) 84.

DOI: 10.1038/nature03028

[9] T. Watanabe, H. Funakubo, M. Osada, Y. Noguchi and M. Miyayama, Appl. Phys. Lett. 80, No.1 (2002).

[10] S. S. Kim, T. K. Song, J. K. Kim and J. Kim, J. Appl. Phys. 92, No.4 (2002)

[11] Y. Noguchi and M. Miyayama, Appl. Phys. Lett. 78, No.13 (2001).

[12] S. Fleischer, P. T. Lai, and Y. C. Cheng: J. Appl. Phys. 73 (1994) 8353.

[13] T. Mihara and H. Watanabe, Part I, Jpn. J. Appl. Phys. 34, 5664 (1995).

[14] Yung-Bin Lin and Joseph Ya-min Lee, J. Appl. Phys. 87, 1841, (2000). Fig. 1. XRD patterns of deposited KNN thin films as a function of oxygen concentration. Fig. 2. AFM images of surface microstructure of deposited KNN thin films . Fig. 3. The surface micro structure morphology of the thin films deposited using optimal parameters. Fig. 4.Wide-scan XPS spectrum of as-deposited KNN thin film. Fig. 5. The capacitance versus applied voltage curves of as-deposited thin film for different oxygen concentration. Fig. 6. The J-E curves of thin film for different oxygen concentration. Fig. 7. The (a) (J/T2) vs E1/2 (b) (J/E) vs E1/2 curves of as-deposited KNN thin films.

DOI: 10.1016/j.tsf.2007.05.027