Preparation of BST thin films on Pt electrode on Si wafer with down-flow LSMCVD reactor |
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| Authors: | Hyun Jin Chung Jin Hong Kim Won Seok Moon Seung Bin Park Cheol Seong Hwang Moon Yong Lee |
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| Affiliation: | 1. Department of Chemical Engineering , Korea Advanced Institute of Science and Technology , 373-1 Kusong-Dong, Yusong-Gu, Taejon, 305-701, Korea;2. Semiconductor R and D center , Samsung electronics Co., Ltd. , San #24 Nongseo-lee, Kiheung-eup, Yongin-gun, Kyungki-do, 449-900, Korea |
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| Abstract: | Abstract A novel type of down-flow LSMCVD (Liquid Source Mist CVD) reactor was developed to prepare a high dielectric BST thin film on Pt electrode on Si wafer. Barium acetate Ba (OOCCH3)2], strontium acetate Sr (OOCCH3)2], and titanium isoproxide Ti (OC3H7 i )4] were used as metal sources. Metal sources were dissolved in acetic acid, 1-butanol, or 2-methoxyethanol. BST Ba/(Ba + Sr) = 0.7] film annealed on Pt/Ti/SiO2/Si above 650°C was polycrystalline. BST film has a (110) preferred orientation with increasing temperature. Surface roughness of BST film and grain size increased with increasing temperature. The metal-oxygen bond was formed at 650°C as shown in the spectra of FTIR. The depth profiles of elements of BST thin films indicated a uniform composition throughout the film. BST films annealed at 750°C showed a dielectric constant and a tanδ of 390 (thickness: 150 nm) and 0.06 at a frequency of 100 kHz, respectively. The behavior of capacitance of the BST film with bias voltage showed paraelectric property. BST film annealed at 750°C had the leakage current density of 3.2 (μA/cm2) at a bias voltage of 2V. |
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| Keywords: | keywords: BST ferroelectric LSMCVD DRAM capacitor |
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