Low temperature rf sputtering deposition of (Ba, Sr) TiO{sub 3} thin film with crystallization enhancement by rf power supplied to the substrate
- System LSI Research Division, Silicon Solution Company, Oki Electric Industry Co., Ltd., 550-1, Higashi-asakawa, Hachioji, Tokyo 193-8550 (Japan)
The (Ba, Sr) TiO{sub 3} thin film deposited by radio frequency (rf) sputtering requires a high deposition temperature near 500 deg. C to realize a high relative dielectric constant over of 300. For example, the film deposited at 330 deg. C contains an amorphous phase and shows a low relative dielectric constant of less than 100. We found that rf power supplied not only to the (Ba, Sr) TiO{sub 3} sputtering target, but also to the substrate during the initial step of film deposition, enhanced the crystallization of the (Ba, Sr) TiO{sub 3} film drastically and realized a high dielectric constant of the film even at low deposition temperatures near 300 deg. C. The 50-nm-thick film with only a 10 nm initial layer deposited with the substrate rf biasing is crystallized completely and shows a high relative dielectric constant of 380 at the deposition temperature of 330 deg. C. The (Ba, Sr) TiO{sub 3} film deposited at higher temperatures (upwards of 400 deg. C) shows <110> preferred orientation, while the film deposited at 330 deg. C with the 10 nm initial layer shows a <111> preferred orientation on a <001>-oriented ruthenium electrode. The unit cell of (Ba, Sr) TiO{sub 3} (111) plane is similar to that of ruthenium (001) plane. We conclude that the rf power supplied to the substrate causes ion bombardments on the (Ba, Sr) TiO{sub 3} film surface, which assists the quasiepitaxial growth of (Ba, Sr) TiO{sub 3} film on the ruthenium electrode at low temperatures of less than 400 deg. C.
- OSTI ID:
- 20637102
- Journal Information:
- Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films, Vol. 23, Issue 3; Other Information: DOI: 10.1116/1.1901676; (c) 2005 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0734-2101
- Country of Publication:
- United States
- Language:
- English
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