• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 C
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• pp.845-847
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• 1999

(Ba, Sr)$TiO_3$[BST] thin films were fabricated on Pt/$TiO_2/SiO_2$/Si substrate by RF sputtering. The structural and dielectric properties of the BST thin films were investigated with the deposition time. Increasing the deposition time from 20 min. to 60 min., second phases were decreased, and EST (111), (100), (200) peaks were increased. The relative dielectric constant and dielectric loss of the EST thin films with the thickness of 3000$\AA$ were 300 and 0.018, respectively at 1[kHz]. The relative dielectric constants was decreased and dielectric losses was increased as increasing the frequency.

• 한국세라믹학회지
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• 제40권4호
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• pp.380-384
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• 2003

The effects of the mole concentrations of precursor solution on the microstructure and dielectric properties of sol-gel deposited $Ba_{0.85}$S $r_{0.15}$Ti $O_3$(BST) thin films have been investigated. The films were of single perovskite phase with strong (100) preferred orientation when grown on LaNi0$_3$ buffered Pt/Ti/ $SiO_2$Si substrates using a diluted precursor solution. Variation of the precursor solution concentration resulted in a different microstructure and, in turn, affected the tunability of the sol-gel deposited films. It was observed that leakage currents increased asymmetrically for the negative and positive bias voltage with decreasing thickness. Overall results suggest that those BST films have acceptable properties f3r applications as room-temperature tunable elements.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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• pp.607-610
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• 2004

The Pb $(Zr_{0.52}Ti_{0.48})O_3/(Ba_{0.6}Sr_{0.4}TiO_3$ [PZT(52/48)/BST(60/40)] heterolayered thin films were fabricated on the Pt/Ti/$SiO_2$/Si by RF sputtering method. The structural properties of the PZT(52/48)/BST(60/40) heterolayered thin films were investigated with Ar/$O_2$ ratio condition. All the PZT(52/48)/BST(60/40) heterolayered thin films had shown the PZT(111), (200) and BST(200) Peaks of the tetragonal structure. Increasing the Ar/$O_2$ ratio, the average roughness was increased. The thickness ratio of the to the PZT and BST thin film was 1:2. In the case of the PZT(52/48)/BST(60/40) heterolayered thin films with Ar/$O_2$ ratio of 80/20, the average roughness was 3.4 [nm].

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.326-326
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• 2010

The dielectric properties of continuous composition spreaded (CCS) $BaTiO_3-SrTiO_3$ (BST) thin filmsgrown at room temperature and annealed at different temperature ($350^{\circ}C$ and $550^{\circ}C$) were investigated. Moreover, electrical properties (leakage current and breakdown voltage) of CCS BST thin films were also investigated. The aluminum top-electrode, sized by $200{\times}200\;{\mu}m2$ and apart from each other by $300\;{\mu}m$, were deposited on the CCS BST thin films by the DC sputtering system. The dielectric properties of the CCS BST thin films were significantly influenced depending on the distance from $BaTiO_3$ and $SrTiO_3$ targets which was attributed to the $BaTiO_3-SrTiO_3$ composition ratio. The maps of dielectric constants and loss tangents were plotted via $1500\;{\mu}m$ - step measuring. The specific points showing the dielectric constant (k: ~300) and loss tangent (tand: ~0.008) at 1 MHz were found.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 C
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• pp.740-742
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• 1998

In this paper, we described the effect of rapid thermal annealing on the electrical properties of interfacial layer between various top electrodes and $(Ba_{0.5}Sr_{0.5})TiO_3$ thin films. BST thin films were fabricated on Pt/TiN/$SiO_2$/Si substrate by RF magnetron sputtering technique. AI, Ag, and Cu films for the formation of top electrode were deposited on BST thin films by thermal evaporator. Top electrodes/BST/Pt capacitor annealed with rapid thermal annealing at various temperature. In $(Ba_{0.5}Sr_{0.5})TiO_3$ thin films with Cu top electrode annealed at $500^{\circ}C$, the dielectric constant was measured to the value of 366 at 1.2 [kHz] and the leakage current was obtained to the value of $5.85{\times}10^{-7}\;[A/cm^2}$ at the forward bias of 2 [V].

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1998년도 추계학술대회 논문집
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• pp.243-246
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• 1998

(Ba, Sr)TiO$_3$[BST] thin films were fabricated on Pt/SiO$_2$/Si substrate by RF sputtering technique. The structural, dielectric and electrical properties of BST thin films were investigated with Ar/O$_2$ ratio. Dielectric constant and dielectric loss of the BST thin film were about 1020 and 2.0[%], respectively. (at RF power 80W, post annealing temperature $650^{\circ}C$, deposition pressure of 5mTorr and Ar/O$_2$=80/20). For the BST(Ar/O$_2$=80/20) thin film with Polarization switching cycles of 10$^{10}$ , remanent polarization and coercive field were 0.084[$\mu$C/cm$^2$], 1.954[kV/cm], respectively.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1997년도 춘계학술대회 논문집
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• pp.309-313
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• 1997

(Ba$_{x}$Sr$_{l-x}$)TiO$_3$(BST) thin fi1ms with various Ba/Sr ratios were deposited on Pt(80nm)/SiO$_2$(100nm)/Si by RF magnetron sputtering. BST thin films which have x=0.6, 0.5, 0.4 were studied dielectric properties with temperature variation. The frequency was used from 100Hz to 1MHz for measuring dielectric constant. The measurement conditions of dielectric constant with Temperature Variation were 1KHz and 2$0^{\circ}C$. As a result, the dielectric constant of BST thin film was about 425 and loss factor was 0.013. Also, with increasing Temperature, the dielectric constants of BST thin films were gradually decreased.sed.

• Transactions on Electrical and Electronic Materials
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• 제1권4호
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• pp.30-39
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• 2000

The variation of electrical properties of (Ba, Sr)TiO$_3$[BST] thin films deposited of RuO$_2$electrode with (Ba+Sr)/Tr ration was investigated. BST thin films with various (Ba+Sr)/Tr ration were deposited on RuO$_2$/Si substrates using in-situ RF magnetron sputtering. It was found that the electrical properties of BST films depends on the composition in the film. The dielectric constant of the BST films is about 190 at the (Ba+Sr)/Tr ration of 1.0, 1,025 and does not change markedly. But , the dielectric constant degraded to 145 as the (Ba+Sr)/Tr ratio increase to 1.0. In particular, the leakage current mechanism of the films shows the strong dependence on the (Ba+Sr)/Tr ration in the films. At the ration (Ba+Sr)/Tr=1,025, the Al/BST/RuO$_2$ capacitor show the most asymmetric behavior in the leakage current density, vs, electric field plot. It is considered that the leakage current of the (Ba+Sr)/Tr=1,025 thin films is controlled by the battier-Iimited process, i,e, Schottky emission.

• 한국세라믹학회지
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• 제32권4호
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• pp.441-447
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• 1995

Ba0.65Sr0.35TiO3 (BST) thin films were deposited on Pt/SiO2/Si(100) substrate by rf magnetron sputtering. The substrate temperature changed from 35$0^{\circ}C$ to 55$0^{\circ}C$ and crystalline BST thin films were deposited above 45$0^{\circ}C$. Most of the films had (111) preferred orientation regardless of deposition temperature, but the films changed to (100) preferred orientation as gas pressure increased. The dielectric constant increased with increasing substrate temperature and film thickness, and ranged from 100 to 600 at room temperature. The leakage current increased as substrate temperature increased or as film thickness decreased.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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• pp.379-382
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• 1998

(Ba, Sr)TiO$_3$[BST] thin films were fabricated on Pt/SiO$_2$/Si substrate by RF sputtering technique. The Mic개structure, dielectric and electrical properties of BST thin films were investigated with sputtering pressure. Dielectric constant and dielectric loss of the deposited thin film at sputtering pressure of 5 mTorr were about 91 and 1.9(%), respectively. Increasing sputtering pressure, leakage current was increased. It was found that leakage current of BST thin films was depended on the sputtering pressure.