• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1999년도 추계학술대회 논문집
• /
• pp.121-124
• /
• 1999

The (Ba,Sr)TiO$_3$[BST] thin film were fabricated on the Pt/Ti/SiO$_2$/Si substrate by RF sputtering technique. The structural properties of the BST thin films were investigated with deposition time and substrate temperature by XRD. In the case of the BST thin films which has the deposition thin of 20 min, second phases and BST (111) peaks were increased with increasing the temperature of substrate. The capacitance of the BST thin film (deposition time of 20 min.) was decreased with the substrate temperature and was 1500pF with applied voltage of 1V.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2006년도 추계학술대회 논문집 전기물성,응용부문
• /
• pp.123-124
• /
• 2006

The sandwiched PZT/$BaTiO_3$/PZT thick films were fabricated by two different methods thick films of the PZT by screen printing method on alumina substrateselectrodes with Pt, thin films of $BaTiO_3$ by the spin-coating method on the PZT thick films and once more thick films of the PZT by the screen printing method on the $BaTiO_3$ layer. The structural and the dielectric properties were investigated for effect of various stacking sequence of sol-gel prepared $BaTiO_3$ coating solution at interface of the PZT thick films, The insertion of BaTi03 interlayer yielded the PZT thick films with homogeneous and dense grain structure with the number of $BaTiO_3$ layers. The leakage current density of the $PZT/BaTiO_3-1$ film is less that $4.41{\times}10^{-9}A/cm^2$ at 5 V.

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

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2000년도 하계학술대회 논문집
• /
• pp.51-54
• /
• 2000

In this paper, $Ba_{0.5}$Sr$_{0.5}$TiO$_3$ thin films were prepared on Pt/Ti/SiO$_2$/Si substrate by RF magnetron sputtering method. We investigated effect of deposition conditions (especially RF input power) on structural properties of BST thin films. Deposit conditions of BST films were set working gas ratio, Ar:O$_2$= 70 : 30, working pressure 10mTorr, and RF input power 25W, 50W, 75W and 100W. Post-annealing using rapid thermal annealing(RTA) performed at 45$0^{\circ}C$, 55$0^{\circ}C$, $650^{\circ}C$, and 75$0^{\circ}C$ in oxigen ambient for 60 sec, respectively. The structural properties of BST films on Pt/Ti/SiO$_2$/Si substrate analysed by X-ray diffraction(XRD).).).

• E2M - 전기 전자와 첨단 소재
• /
• 제8권1호
• /
• pp.77-82
• /
• 1995

PTCR(Positive Temperature Coefficient of Resistivity) thermistor in thin film BaTiO$_{3}$ system was prepared by using radio frequency(13.56 MHz) and DC magnetron sputter equipment. Polycrystalline, surface structure, and R-T(Resistivity-Temperature) characteristics of the specimens were measured by X-ray diffraction(D-Max3, Rigaku, Japan), SEM(Scanning Electron Microscopy: M.JSM84 01, Japan), and insulation resistance measuring system (Keithley 719), respectively. Thin films characteristics of the thermistor showed different properties depending on the substrate even with the same sputtering condition. The thin film formed on the A1$_{2}$O$_{3}$ substrate showed a good crystalline and a low resistivity at below curie point. However, the thin films prepared on slide glass and Si wafer were amorphous. The thicknesses of the three samples prepared under the same process conditions were 700[.angs.], 637.75[.angs.], and 715[.angs.], respectively.

• Bulletin of the Korean Chemical Society
• /
• 제29권2호
• /
• pp.427-430
• /
• 2008

BaTiO3 and SrTiO3 thin films were fabricated on Pt/Ti/SiO2/Si substrate by the pulsed laser deposition process. The dependence of the deposited film quality upon the partial oxygen pressure during the deposition process was importantly examined. Regardless of the oxygen pressure, the as-deposited films were not fully crystallized. However, the film deposited at low oxygen pressure became well crystallized after the annealing process. It was concluded, therefore, that the partial oxygen pressure is reduced as low as possible during the deposition process and then anneal the as-deposited samples at ambient pressure to fabricate the well crystallized SrTiO3 and BaTiO3 films by laser ablation.

• 한국전기전자재료학회논문지
• /
• 제15권11호
• /
• pp.933-938
• /
• 2002

(Ba,Sr)TiO$_{4}$ (BST) thin films on Pt/Ti/SiO$_{2}$/Si substrates were deposited by a sol-gel method and the etch characteristics of BST thin films have been investigated as a function of gas mixing ratio. The maximum etch rate of the BST films was 440 $AA$/min under such conditions as: CF$_{4}$(CF$_{4}$＋Ar) of 0.2, RF-power of 700 W, DC-bias voltage of -200 V, pressure of 15 mTorr and substrate temperature of 30 $^{circ}C$. The selectivities of BST to Pt, SiO$_{2}$ and PR were 0.38, 0.25 and 0.09, respectively. In the XPS (X-ray photoelectron spectroscopy) analysis, Barium (Ba) and Strontium (Sr) component in BST thin films formed low volatile compounds such as BaFx, SrFx, which are forms by the chemical reaction with F atoms and is removed by Ar ion bombardment. Titanium (Ti) is removed by chemical reaction such as TiF with ease. The result of secondary ion mass spectrometry (SIMS) analysis confirmed the existence of the BaFx, SrFK, TiFx.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
• /
• pp.565-568
• /
• 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/SiO2/Si substrate. 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 10-7 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 $BBa_{0.6}Sr_{0.4}TiO_3$ thin films were 333,0.0095, and 31.1%, respectively.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제49권5호
• /
• pp.265-269
• /
• 2000

$(Ba, Sr)TiO_3$thin films were etched with a magnetically enhanced inductively coupled plasma (MEICP) at different CF4/Ar gas mixing ratios. Experimental was done by varying the etching parameters such as rf power, dc bias and chamber pressure. The maximum etch rate of the BST films was $1800{AA}/min$ under $CF_4/(CF_4+Ar)$ of 0.1, 600 W/350 V and 5 mTorr. The selectivity of BST to Pt and PR was 0.6, 0.7, respectively. X-ray photoelectron spectroscopy (XPS) results show that surface reaction between Ba, Sr, Ti and C, F radicals occurs during the (Ba, Sr)TiO3 etching. To analyze the composition of surface residue after the etching, films etched with different CF_4/Ar$ gas mixing ratio were investigated using XPS and secondary ion mass spectroscopy (SIMS).

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1994년도 춘계학술대회 논문집
• /
• pp.17-20
• /
• 1994

PTCRl(positive temperature coefficient of resistivity) thermistors in the thin file BaTiO$_3$ system were deposited by radio frequency (13.56 MHz) and dc radio frequency (13.56MHz) and dc magnerton sputter equipment. R-T(resistivity -temperature) properties was investigated as a function of substrate and the temperature variation. The specimens make a comperison between the thin films and the bulk in the resistivity variation. Substrate temperature. deposition time. and forward power are deposited at the 400$^{\circ}C$, 10 hours, and 210 watt. respectively. The aim of this work is to obtain lower than bulk specimen resistivity in thin films BaTiO$_3$ system thermistor by RF/DC magnetron sputter equipment.