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

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

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2002년도 춘계학술대회 논문집 센서 박막재료 반도체재료 기술교육
• /
• pp.16-19
• /
• 2002

(Ba,Sr)TiO3(BST) thin film is an attractive material for the application in high-density dynamic random access memories (DRAMs) because of the high relative dielectric constant and small variation in dielectric properties with frequency. In this study, (Ba0.6,Sr0.4)TiO3 thin films on Pt/Ti/SiO2/Si substrates were deposited by a sol-gel method and the CF4/Ar inductively coupled plasma (ICP) etching behavior of BST thin films had been investigatedby varying the process parameters such as chamber pressure, ICP power, and substrate bias voltage. To analysis the composition of surface residue following etching BST films etched with different Ar/CF4 gas mixing ratio were investigated using x-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometer (SIMS).

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1999년도 추계학술대회 논문집
• /
• pp.33-36
• /
• 1999

In this paper, $Ba_{0.5}$Sr$_{0.5}$TiO$_3$ thin-films were prepared on Pt/Ti/Si0$_2$/Si substrates by RF magnetron sp-uttering method. We investigated electric and dielectric properties of BST thin-films with various ann-ealing temperature using in-sute RTA. Deposition conditions of BST films were set substrate temperat-ure, 30$0^{\circ}C$ and working gas ratio, Ar:O$_2$=90:10. After BST films deposited, we fabricated a capacitor of MIM structure with Al top electrode for measurement. Post-annealing using RTA performed at 40$0^{\circ}C$, $600^{\circ}C$, 80$0^{\circ}C$ for 60 sec, respectively. Also we exacted crystallization and composition of BST thin-films by XRD analysis. In measurement result, this capacitors showed a dielectric constant of about 200 at 1MHz and leakage current density of 5$\times$10$^{-8}$ A/$\textrm{cm}^2$ at 1.5V Microstructure of BST thin-films exhibited effective quality in low-temperature annealed 71ms than high-temperature annealed 71ms.s.s.

• 한국결정성장학회지
• /
• 제11권2호
• /
• pp.60-66
• /
• 2001

($Ba_x$$Sr_{1-x}$)$TiO_3$ (x=0.9, 0.7, 0.5)박막을 졸-겔법으로 ITO-coated glass기판 위에 제조하였다. BST의 perov-skite상 생성온도는 $600^{\circ}C$ 이상이며 Sr함량이 증가할수록, $Ba^{2+}$ 이온보다 작은 $Sr^{2+}$ 이온에 의해 perovskite상들의 피크가 높은 회절 각도로 이동하였다. 그리고 온도가 증가할수록 결정립은 조대화 되었고, Sr 함량이 증가할수록 결정립은 미세화 되었다. BST(50/50)의 유전상수 값은 다른 두 조성보다 큰 값을 나타내고 유전손실 값은 더 낮았다. 1 kHz때의 BST(50/50)박막의 유전상수 및 유전손실 값은 각각 652와 0.042였다.

• 한국재료학회:학술대회논문집
• /
• 한국재료학회 1993년도 추계 학술발표 강연 및 논문 개요집
• /
• pp.119-120
• /
• 1993

• 한국재료학회:학술대회논문집
• /
• 한국재료학회 1996년도 재료학회 추계학술발표회
• /
• pp.57-57
• /
• 1996

• 한국재료학회:학술대회논문집
• /
• 한국재료학회 1996년도 재료학회 춘계학술발표회
• /
• pp.17-17
• /
• 1996

• 한국재료학회:학술대회논문집
• /
• 한국재료학회 1994년도 춘계 학술발표 강연 및 논문 개요집
• /
• pp.113-113
• /
• 1994

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
• /
• pp.244-247
• /
• 2002

NdBaCuO thin films were prepared on $SrTiO_{3}$ substrates by RF magnetron sputtering. These as-grown films were classified into 3type. The resistivity of the deposited films are usually lower than of the YBCO film. The Tc (onset) and Tc (R=0) in the optimized thin films are as high as 90 and 80K, respectively. These as-grown films are highly uniform and semi-trans parent and have a room temperature resistivity of $0.3m{\Omega}cm$.