• Korean Journal of Materials Research
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• v.3 no.2
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• pp.158-165
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• 1993

Abstract To investigate the effect of underlying Si on the thermal stability of the TiS$i_2$ film, TiS$i_2$ films obtained by the solid-state reaction of the Ti film on as-deposited or on heat-treated poly-silicon and amorphous-silicon were annealed at 90$0^{\circ}C$ for various times. The poly-Si film was evaluated by XRD, SEM and TEM. The thermal stability of the TiS$i_2$ film was evaluated by measuring the sheet resistance and microstructural evolution during furnace annealing. Agglomeration of the TiSi, film occurred more on amorphous-Si than on poly-Si. The thermal stability of the TiS$i_2$ film was improved by annealing poly-Si. The Si layer crystallized from amorphous-Si has an equiaxed structure with the (111) preferred orientation whereas for as-deposited poly-Si has a columnar structure with the (110) orientation. Better thermal stability of the TiS$i_2$ film can be obtained by the higher surface energy of underlying poly-Si.

• Proceedings of the KIEE Conference
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• 2005.11a
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• pp.87-89
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• 2005

$Bi_{3.25}Y_{0.75}Ti_{3}O_{12}$[BYT] ferroelectric thin films were deposited by RF-Sputtering method on the $Pt/Ti/SiO_2/Si$. We investigated the effects of processing condition (especially post-annealing) on the structural and ferroelectric properties of the BYT thin films. Increasing the annealing temperature, the peak intensity of (117) increased and c-axis orientation decreased. The BYT thin films crystallized well at $600^{\circ}C$ for 30min. No secondary phases observed in the XRD pattern. At annealing temperature of $700^{\circ}C$, the thin films had no cracks and the grain was uniform. The calculated lattice constants of BYT thin films were a=0.539nm, b=0.536nm, c=3.288nm. The remnant polarization of the $Bi_{3.25}Y_{0.75}Ti_{3}O_{12}$ capacitor reached $1.8uC/cm^2$ at an applied field about 400kV/cm. The BYT thin films can be used as capacitors in Ferroelectric Random Access Memory device.

• Electrical & Electronic Materials
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• v.9 no.2
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• pp.132-137
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• 1996

Pb(Zr$_{x}$Ti$_{1-x}$ )O$_{3}$ solutions prepared by sol-gel processing with different Zr/Ti ratio were coated on Pt/SiO$_{2}$/Si substrates using spin coating method. Coated films were annealed by rapid thermal annealing at 650.deg. C for 20sec to fabricate Pb(Zr, Ti)O$_{3}$ ferroelectric thin films. Electrical properties of the films such as dielectric constant and loss, ferroelectric hysteresis, fatigue, switching time, and leakage current were measured. Hysteresis of the films with different Zr/Ti ratio yield Pr ranging 10-21.mu.C/cm$^{2}$, E$_{c}$ ranging 37.5-137.5kV/cm. Hysteresis curve was changed from square-type to slim type according to increasing Zr contents. Switching time was faster than 180ns, and leakage current was about 20.mu.A/cm$^{2}$. The film underwent above 10$^{8}$ cycles of reversed polarization showed fatigue with increased coercive field and decreased remnant polarization.tion.

• Journal of the Korean institute of surface engineering
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• v.25 no.5
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• pp.215-221
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• 1992

This research is aimed at developing(110) preferred TiS2 cathode films and glass typed solid electro-lytes which have high ionic migrations and low electron conductivities for thin secondary solid batteries. To obtain preferred oriented TiS2 thin films on a substrate by CVD method using TiCl4 and H2S gases three factors of heating temperature, inner pressure of furnace and TiCl4/H2S gas mole fraction were ex-amined systematically. To obtain solid films of Li2O-B2O3-SiO2 electrolytes by r.f. sputtering for thin proto-type batteries of Li/Li2O-B2O3-SiO2TiS2, sputtering conditions were examined. TiS2 cathode films showed columnar structure, namely c axis oriented parallely. At low pressure of reaction chamber and low heating temperature, surface of smooth TiS2 films couldd be obtained. Ionic conductivity of Li2O-B2O3-SiO2 films manufactured by r.f. magnetron sputtering were 3$\times$10-7$\Omega$-1cm-1 and electron conductivities were 10-11$\Omega$-1cm-1. Open cell voltage of thin lithium batteries were 2.32V with a designed prototype cell.

• Journal of the Korean Vacuum Society
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• v.11 no.3
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• pp.135-140
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• 2002

In this paper, We deposited the BST thin-film on p-type (100)Si, (100)MgO and MgO/Si substrates respectively using RF magnetron sputtering method. After the BST thin-fil m was deposited, we performed RTA(rapid thermal anneal) at $600^{\circ}C$, oxygen atmosphere and 1 min. In the XRD measurement, we observed the (110) $Ba_{0.5}Sr_{0.5}TiO_3$ main peak in all samples and the peak intensity increased after post annealing. Then we manufactured a capacitor using Al Electrode and measured I-V, C-V. In C-V measurement result values for each substrate, dielectric constant was calculated 120 (bare Si), 305(MgO/Si), 310(MgO) respectively. A leakage current density was present less than 1 $\mu\textrm{A/cm}^2$ at applied fields below 0.3 MV/cm. In conclusion we confirmed that MgO/Si substrates give good results for BST thin-film deposition.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.04b
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• pp.88-91
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• 2000

The $(Sr_{0.85}Ca_{0.15})TiO_3$(SCT) thin films are deposited on Pt-coated electrode(Pt/TiN/$SiO_2$/Si) using RF sputtering method. The crystallinity of SCT thin films is increased with increase of substrate temperature in the temperature range of 200~500$[^{\circ}C]$. V-I characteristics of SCT thin films show the increasing leakage current with the increases of deposition temperature. The conduction mechanism of the SCT thin films observed in the temperature range of 25~100$[^{\circ}C]$ can be divided into four characteristic regions with different mechanism by the increasing current.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.44 no.7
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• pp.914-918
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• 1995

In this study, Pb(Zr$_{x}$ Ti$_{1-x}$ )O$_{3}$ (x=0.65, 0.52, 0.35) thin films were fabricated by Sol-Gel method. A stock solution with excess Pb 10[mol%] of Pb(Zr$_{x}$ Ti$_{1-x}$ )O$_{3}$ was made and spin-coated on the Pt/SiO$_{2}$/Si substrate at 4000[rpm] for 30[sec.]. Coated specimens were dried on the hot-plate at 400[.deg. C] for 10[min.]. Sintering temperature and time were 500~800[.deg. C] and 1~60[min.]. The coating process was repeated 6 times and the final thickness of the thin films were about 4800[A]. To investigate crystallization condition, PZT thin films were analyzed with sintering temperature, time and composition by the XRD. The microstructure of thin fulms were investigated by SEM. The ferroelectric perovskite phases precipitated under the sintering of 700[.deg. C] for 1 hours. In the PZT(52/48) composition, dielectric constant and dielectric loss were 2133, 2.2[%] at room temperature, respectively.ively.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.6
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• pp.486-491
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• 2002

We have fabricated $Bi_{3.25}La_{0.75}Ti_3O_12$ (BLT) thin films on the Pt/Ti/$SiO_2$/Si substrates using a metalorganic decomposition (MOD) method with annealing temperature from $550^{\circ}C$ to $750^{\circ}C$. The structural properties of BLT films examined by x-ray diffraction (XRD). From XRD analysis. BLT thin films show polycrystalline structure. The layered-perovskite phase was obtained by spin-on films at above $600^{\circ}C$ for 1h. Scanning electron microscopy (SEM) showed uniform surface composed of rodlike grains. The grain size of BLT films increased with increasing annealing temperature. The BLT film annealed at $650^{\circ}C$ was measured to have a dielectric constant of 279, dielectric loss of 1.85(%), remanent polarization of $25.66\mu C/\textrm{cm}^2$, and coercive field of 84.75 kV/cm. The BLT thin films showed little polarization fatigue test up to $3.5{\times}10^9$ bipolar cycling at 5 V and 100 kHz.

• Journal of the Microelectronics and Packaging Society
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• v.10 no.2
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• pp.7-12
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• 2003

The $Bi_{3.3}La_{0.7}O_{12}$(BLT) capacitors with Metal-Ferroelectric-Insulator-Silicon structure were prepared on $SiO_2/Si$ substrates by using sol-gel method. The BLT thin films annealed at $650^{\circ}C$ and $700^{\circ}C$ showed randomly oriented perovskite crystalline structures. The full with at half maximum (FWHM) of the (117) main peak was decreased from $0.65^{\circ}$ to $0.53^{\circ}$ with increasing the annealing temperature from $650^{\circ}C$ to $700^{\circ}C$, indicating the improvement in the crystalline quality of the film. In addition, the grain size and $R_rms$ , values were increased with increasing the annealing temperatures, showing the rough film surface at higher annealing temperatures. From the capacitance-voltage (C-V) measurements, the memory window voltage of the BLT film annealed at $700^{\circ}C$ was found to be about 0.7 V at an applied voltage of 5 V. The leakage current density of the BLT film annealed at $700^{\circ}C$ was about $3.1{\times}10^{-8}A/cm^2$.

• Journal of the Korean Ceramic Society
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• v.38 no.12
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• pp.1137-1143
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• 2001

In this study, glass-ceramics containing cordierite(2MgO$.$2Al$_2$O$_3$5SiO$_2$) as a major crystalline phase was prepared from MAS (MgO-Al$_2$O$_3$-SiO$_2$) glass system for the application to reflector. Glasses prepared with addition of TiO$_2$as a nucleating agent were crystallized by two-step heat treatment of nucleation and crystal growth. Then nucleation and crystal growth behavior were investigated and the influence of heat treatment schedule on the nature of crystal phases and the diffuse reflectance spectrum was investigated. As a result, cordierite and rutile were precipitated as a major crystalline phases for the glass-ceramics with the nucleation at 750$^{\circ}C$ for 3 hours and then crystallization at 1100$^{\circ}C$ for 5 hours, and this glass-ceramics showed the reflectance over 90% in 570∼2500nm specturm region.