• 한국전기전자재료학회논문지
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• 제13권7호
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• pp.592-597
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• 2000

In this study (B $a_{0.5}$/S $r_{0.5}$)Ti $O_3$[BST(50/50)] ceramic thin films were prepared by the Sol-Gel method BST(50/50) stock solution was made and spin-coated on the Indium Tin Oxide(ITO)/glass substrate at 4000 rpm for 30 seconds. The coated films were dried at 35$0^{\circ}C$ for 10 minutes and annealed at 650~75$0^{\circ}C$ for 1 hour. The microstructural properties of the BST(50/50) thin film were studied by the XRD and AFM. The ferroelectric perovskite phase was formed at the annealing condition of 75$0^{\circ}C$ for 1 hour. Dielectric constant and loss of this thin were 370, 3.7% at room temperature respectively. The polarization switching voltage showed the good value of 3V. The leakage current density of the BST(50/50) thin film was 10$^{-7A}$c $m^2$with applied voltage of 1.5V. BST(50/50) thin film capacitors having good dielectric and electrical properties are expecting for the application to the dielectric material of DRAM.RAM.M.

• Bulletin of the Korean Chemical Society
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• 제23권5호
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• pp.741-744
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• 2002

Single phase of multicomponent oxide ZrTiO4 film could be prepared through surface sol-gel route simply by coating the mixture of 100 mM zirconium butoxide and titanium butoxide on $Pt/Ti/SiO_2Si(100)$ substrate, following pyro lysis at $450^{\circ}C$, and annealing it at 770 $^{\circ}C.$ The dielectric constant of the film was reduced as the film thickness decreased due to of the interfacial effects caused by layer/electrode and a few voids inside the multilayer. However, the dielectric property was independent of applied dc bias sweeps voltage (-2 to +2 V).The dielectric constant of bulk film, 31.9, estimated using series-connected capacitor model was independent of film thickness and frequency in the measurement range, but theoretical interfacial thickness, ti, was dependent on the frequency. It reached a saturated ti value, $6.9{\AA}$, at high frequency by extraction of some capacitance component formed at low frequency range. The dielectric constant of bulk ZrTiO4 pellet-shaped material was 33.7 and very stable with frequency promising as good applicable devices.

• 한국전기전자재료학회논문지
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• 제17권8호
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• pp.852-858
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• 2004

An alkoxide-based sol-gel method was used to fabricate $Ba_{0.6}Sr_{0.4}TiO_{3}$thin films doped by Bi from 5 to 20 mol% on a Pt/Ti/$SiO_2$/Sisubstrate. The structural and dielectric properties of BST thin films were investigated as a function of Bi dopant concentration. The dielectric properties of the Bi doped BST films were strongly dependent on the Bi contents. The dielectric constant and dielectric loss of the films decreased with increasing Bi content. However, the leakage current density of the 10 mol% Bi doped $Ba_{0.6}Sr_{0.4}TiO_{3}$ thin film showed the lowest value of 5.13$\times 10^{-7} A/{cm}^2$ at 5 V. The figure of merit (FOM) reached a maximum value of 32.42 at a 10 mol% Bi doped $Ba_{0.6}Sr_{0.4}TiO_{3}$thin films. The dielectric constant, loss factor, and tunability of the 10 mol% Bi doped $Ba_{0.6}Sr_{0.4}Tio_{3}$ thin films were 333, 0.0095, and 31.1%, respectively.

• Journal of Electrochemical Science and Technology
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• 제10권4호
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• pp.394-401
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• 2019

The unique study of TiO₂ sol-gel modified carbon paste electrode (CPE) nanocomposites have been developed for electrochemical sensor detecting fipronil pesticide compound. We develop the easy synthesized TiO₂ via a sol-gel method and modified in CPE which applied electrochemical system as cyclic voltammetry (CV) because the concentration is proportional with current peaks. We discover the TiO₂ optimal mass used of 0.1 g which is compared with 0.7 g carbon and 0.3 mL paraffin. It has high-current anodic (Ip_a) of 1.13×10³ μA and high-current cathodic (Ip_c) -0.96×10³ μA in scan rate of 0.5 V/s. The limit of detection (LOD) of fipronil has been determined of 34.0×10^-5 μM in percent recovery of 0.8%. Its high-stability for lifetime TiO₂-CPE nanocomposites was expressed for 13 days which mean that can be used for detecting fipronil pesticide.

• 전기학회논문지
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• 제60권3호
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• pp.584-587
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• 2011

In this work, the $TiO_2$ and $SnO_2$ thin films as blocking layers were coated directly onto the metal-mesh electrode surface to prevent unnecessary inflow of back-transfer electrons from the electrolyte ($I^-/I_3^-$) to the metal-mesh electrode. The DSCs were fabricated with working electrode of SUS mesh coated with blocking $TiO_2$ and $SnO_2$ layers, dye-attached mesoporous $TiO_2$ film, gel electrolyte and counter electrode of Pt-deposited F:$SnO_2$. From the experimental result, it was ascertained that the efficiency of metal electrode coated with $TiO_2$ by Dip-coating was superior to that of metal electrode coated with $SnO_2$ by Dip-coating and screen printing with the results of experiments. The photo-current conversion efficiency of the cell obtained from optimum fabrication condition was 3% ($V_{oc}$=0.61V, $J_{sc}$=11.64 mA/$cm^2$, ff=0.64) under AM1.5, 100 mW/$cm^2$ illumination.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.377-380
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• 2001

The BST thin films to composite (Ba$\sub$x/Sr$\sub$l-x/)TiO$_3$ using sol-gel method were fabricated on Pt/Ti/SiO$_2$/Si substrate. The thin film capacitor to be ferroelectric materials was investigated by structural and electrical properties. BST solution was composited by moi ratio, and then spin-coated (from 3 times to 5 times coating on Pt/SiO$_2$/Si substrate. Thickness of BST ceramics thin films are about 2600∼2800[${\AA}$] in 3 times deposition. The property of leakage current was stable when the applied voltage was 3[V]. Leakage current of 3 times coated BST thin film was 10$\^$-9/∼10$\^$-11/[A] at 0∼3[V].

• 한국재료학회지
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• 제32권9호
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• pp.384-390
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• 2022

A spin coating process for RRAM, which is a TiN/TiO₂/FTO structure based on a PTC sol solution, was developed in this laboratory, a method which enables low-temperature and eco-friendly manufacturing. The RRAM corresponds to an OxRAM that operates through the formation and extinction of conductive filaments. Heat treatment was selected as a method of controlling oxygen vacancy (V_O), a major factor of the conductive filament. It was carried out at 100 ℃ under moisture removal conditions and at 300 ℃ and 500 ℃ for excellent phase stability. XRD analysis confirmed the anatase phase in the thin film increased as the heat treatment increased, and the Ti³⁺ and OH- groups were observed to decrease in the XPS analysis. In the I-V analysis, the device at 100 ℃ showed a low primary SET voltage of 5.1 V and a high ON/OFF ratio of 10⁴. The double-logarithmic plot of the I-V curve confirmed the device at 100 ℃ required a low operating voltage. As a result, the 100 ℃ heat treatment conditions were suitable for the low voltage driving and high ON/OFF ratio of TiN/TiO₂/FTO RRAM devices and these results suggest that the operating voltage and ON/OFF ratio required for OxRAM devices used in various fields under specific heat treatment conditions can be compromised.

• 마이크로전자및패키징학회지
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• 제10권2호
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• pp.7-12
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• 2003

졸-겔(Sol-Gel)법으로 $SiO_2/Si$ 기판 위에 $Bi_{3.3}La_{0.7}O_{12}$(BLT) 강유전체 박막을 스핀코팅하여 Metal-Ferroelectric-Insulator-Silicon 구조의 캐패시터 소자를 제작하였다. 열처리하지 않은 BLT 박막시료를 $650^{\circ}C$와 $700^{\circ}C$의 온도에서 열처리함으로서 임의 배향을 가지는 퍼롭스카이트 결정구조를 나타내었다. 열처리 온도를 $650^{\circ}C$에서 $700^{\circ}C$로 증가시킴에 따라서 (117) 주피크의 full width at half maximum(FWHM)값이 약 $0.65^{\circ}$에서 $0.53^{\circ}$로 감소하여 결정성이 개선되었으며 결정립 크기와 $R_rms$ 값이 증가하면서 박막표면이 거칠어지는 경향을 보여주었다. $700^{\circ}C$에서 열처리한 BLT 박막시료에 대해 인가 전압에 따른 정전용량(C-V)값을 측정한 결과 5V의 인가전압에서 메모리 원도우 값이 약 0.7V를 보여주었으며, 3V의 인가전압에서 누설전류 값이 약 $3.1{\times}10^{-8}A/cm^2$을 나타내었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.341-342
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• 2006

Gadolinium-substituted bismuth titanate, $Bi_{3.3}Gd_{0.7}Ti_3O_{12}$ (BGT), thin films were successfully fabricated on Pt(111)/Ti/$SiO_2$/Si substrates by a sol-gel method and their structural and ferroelectric properties have been characterized. Fabricated BGT thin films were found to be random orientations, which were confirmed by X-ray diffraction experiment and scanning electron microscope analysis. The remanent polarization ($2P_r$)) of BGT thin film annealed at $720^{\circ}C$ was $25.85\;{\mu}C/cm^2$ at an applied voltage of 5 V. The BGT thin films exhibited a 11 % reduction in their switching charge after no less than $10^{11}$ switching cycles at a frequency of 1 MHz.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2002년도 춘계 기술심포지움 논문집
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• pp.173-176
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• 2002

B $i_{3.3}$L $a_{0.7}$ $Ti_{3}$ $O_{12}$(BLT) 강유전체 박막을 Pt/Ti/ $SiO_2$/Si 기판위에 졸-겔법 (sol-gel method) 으로 스핀코팅하여 Metal-Ferroelectric-Metal(MFM) 구조의 커패시터를 형성하였다. BLT 박막의 결정성은 후속열처리 온도가 증가할수록 향상되었으며 $R_{근}$값은 as~coated된 BLT 박막의 경우 3.8$\AA$를 나타내었으나 열처리 온도를 $700^{\circ}C$로 증가한 경우 12.9$\AA$으로 거칠은 표면형상으로 변화되었다. $650^{\circ}C$로 열처리된 BLT 박막의 잔류분극 2Pr ($\pm$($P^{*}$ -$P^{ ^}$))값은 5V 인가전압에서 약 29.1 $\mu$C/$cm^2$을 나타내었다. 또한 $10^{10}$ 스위칭 cycles 가지 분극 스위칭을 반복한 후에도 뚜렷한 잔류분극의 변화를 발견할 수 없어서 우수한 피로특성을 나타내었다. 3V 전압에서 BLT 박막의 누설전류는 약 2.2$\times$$10^{-8}$ A/$cm^2$를 나타내었다.내었다.었다.