• Journal of the Korean Ceramic Society
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• v.31 no.2
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• pp.171-176
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• 1994

The spin-casted PLZT(9/65/35) thin films through polymeric sol-gel process were prepared on Pt substrate. The crack-free, uniform and dense films were obtained by post-annealing at the temperature between 35$0^{\circ}C$ and $700^{\circ}C$. The composite structure mixed together with large grains called "rosette" and surrounding small grains were observed on the films annealed over $600^{\circ}C$. Pyrochlore phase was completely changed to perovskite phase above $600^{\circ}C$ with the increase of annealing temperature. Dielectric constant (k) was larger with the increase of film thickness and annealing temperature. from the measurements of dielectric constant as a function of measuring temperature, it was also observed that Curie temperature was shifted to higher temperature with the increase of film thickness and annealing temperature. The pyroelectric coefficient(P) of 10 times coated film annealed at $700^{\circ}C$ was 65 $\mu$C/$\textrm{cm}^2$.K.$.K.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.777-779
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• 2002

We report the performance of pentacene-based organic thin film transistors (OTFT) with PMMA (polymethyl methacrylate) as the gate insulator which was spin-coated on the ITO (indium tin oxide) glass substrate which was used as the gate contact. The pentacene thin film was deposited on the PMMA film and then Au source/drain contacts were deposited through shadow mask. The pentacene film shows better molecular ordering on PMMA compared with $SiO_2$ of Si wafer. The devices exhibited the field effect mobility of ${\sim}0.004cm^2$/Vs and on/off current ratio of ${\sim}10^3$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.7
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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.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.1030-1035
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• 2001

Strontium barium niobate, (Sr$\sub$0.5/Ba$\sub$0.5/Nb$_2$O$\sub$6/), thin films of various composition were prepared by the sol-gel method. Solution derived from acetate powders and niobium ethoxide in a mixture of acetic acid, ethylene glycol and 2-methoxyehanol was spin-coated onto bare silicon, Pt-coated silicon and fused silica substrates. Processing parameters were optimized to develop stable solutions which yielded films with relatively low crystallization temperatures. It was determined that ethylene glycol was a necessary component of the solution to increase stability against precipitation and to decrease the crystallization temperature of the films as confirmed by XRD and FT-IR analyses.

• 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.

• Bulletin of the Korean Chemical Society
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• v.31 no.10
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• pp.2755-2756
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• 2010

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.12
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• pp.1092-1098
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• 2006

The influence of the concentration of precursor solution and the number of solution coatings on the densification of the $Pb(Zr_xTi_{1-x})O_3$ (PZT) thick films was studied. PZT powder and PZT precursor solution were prepared by3 sol-gel method and PZT thick films were fabricated by the screen-printing method on the alumina substrates. The composition of powder and precursor solution were PZT(70/30) and PZT(30/70), respectively. The PZT precursor solution was spin-coated on the PZT thick films. A concentration of a coating solution was 0.5 to 2.0 mol/L[M] and the number of coating was repeated from 0 to 6. The XRD patterns of all PZT thick films shelved typical perovskite polycrystalline structure. The porosity of the thick films was decreased with increasing the number of coatings and 6-time coated films with 1.5 M showed the dense microstructure and thickness of about $60{\mu}m$. The relative dielectric constant of the PZT thick film was increased with increasing the number of solution coatings and the thick films with 1.5 M, 6-time coated showed the 698. The remanent polarization the 1.5 M and 6-time coated PZT thick films was $38.3{\mu}C/cm^2$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.247-250
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• 2001

Organic semiconductors based on vacuum-deposited films of fused-ring polycyclic aromatic hydrocarbon have great potential to be utilized as an active layer for electronic and optoelectronic devices. We have fabricated organic thin film transistors(OTFTs) and discuss electrical characteristics of the devices. For the gate dielectric layer, OPTMER PC403 photoacryl(JSR Co.) was spin-coated and cured at 220$^{\circ}C$. Electrical characteristics of the device were investigated, where the photoacryl dielectric layer thickness and pentacene active layer thickness were about 0.6$\mu\textrm{m}$ and 800${\AA}$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.11a
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• pp.122-125
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• 1995

Using metalorganic deposition technique, $La_2Ti_2O_{7}$ precursor solution was deposited on platinium coated SiO$_2$/SI(100) substrates by spin-coating process. Crystalline and crack-free films of ∼0.2$\mu\textrm{m}$ thickness were successfully fabricated on the above substrate from four different types of $La_2Ti_2O_{7}$ precursor solutions by proper heat treatment in the temperature range of $700^{\circ}C$∼$1200^{\circ}C$. Microstructure and X-ray diffraction analysis of $La_2Ti_2O_{7}$ thin film showed that the crystallization temperature and the preferred orientation of $La_2Ti_2O_{7}$ thin film were strongly dependent on the precursor used.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.577-578
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• 2006

In this paper, PZT(20/80) thick films were fabricated by the screen-printing method. And the PZT(80/20) coating solution was synthesized by the sol-gel method. PZT(20/80) thick films were screen-printed on the alumina substrates. PZT(80/20) thin film was spin-coated on the PZT(20/80) thick films to obtain densification. And the structural and electrical properties of PZT thick films were investigated with variation of sintering temperature. The PZT specimen sintered at 650f showed good relative dielectric constant of 219 and dielectric loss of 2.45%. Also the remanent polarization and the coercive field were 16.48${\mu}C/cm^2$ and 35.48kV/cm, respectively.