• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.302-302
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• 2007

The $SrRuO_3$/Si thin film electrodes are grown with (00l) preferred orientations on SrO buffered-Si (001) substrates by pulsed laser deposition. The optimum conditions of SrO buffer layers for $SrRuO_3$ preferred orientations are the deposition temperature of $700^{\circ}C$, deposition pressure of $1\;{\times}\;10^{-6}\;Torr$, and the thickness of 6 nm. The 100nm thick-$SrRuO_3$ bottom electrodes deposited above $650^{\circ}C$ on SrO buffered-Si (001) substrates have a rms roughness of approximately $5.0\;{\AA}$ and a resistivity of 1700 -cm, exhibiting a (00l) relationship. The 100nm thick-$Pb(Zr_{0.2}Ti_{0.8})O_3$ thin films deposited at $575^{\circ}C$ have a (00l) preferred orientation and exhibit $2P_r$ of $40\;C/cm^2$, $E_c$ of 100 kV/cm, and leakage current of about $1\;{\times}\;10^{-7}\;A/cm^2$ at 1V.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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• pp.51-54
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• 2003

Tb-doped lead zirconate titanate($Pb_{1.1}(Zr_{0.6}Ti_{0.4})O_3$; PZT) thin films on $Pt(111)/Ti/SiO_2/Si(100)$ substrates prepared by a sol-gel method. Films have a Zr/Ti ratio of 60:40 and perovskite phase structure. The effect on the structural and electrical properties of films measured according to Tb content. Dielectric and ferroelectric properties of PZT thin films were altered significantly by Tb-doping. The PZT thin film with higher dielectric constant and improved leakage current characteristic was obtained by adding 0.3 mol% Tb. At 100 kHz, the dielectric constant and the dielectric loss of the 0.3 mol% Tb-doped PZT thin film were 1611 and 0.24, respectively The remanent polarization(2Pr) of the 0.3 mol% Tb-doped PZT thin film was $61.4\;{\mu}C/cm^2$ and the coercive field was 61.9 kV/cm. Tb-doped PZT thin films showed improved fatigue characteristics comparing to the undoped PZT thin film.

• 한국재료학회지
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• 제20권5호
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• pp.257-261
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• 2010

A non-volatile resistive random access memory (RRAM) device with a Cr-doped $SrZrO_3/SrRuO_3$ bottom electrode heterostructure was fabricated on $SrTiO_3$ substrates using pulsed laser deposition. During the deposition process, the substrate temperature was $650^{\circ}C$ and the variable ambient oxygen pressure had a range of 50-250 mTorr. The sensitive dependences of the film structure on the processing oxygen pressure are important in controlling the bistable resistive switching of the Cr-doped $SrZrO_3$ film. Therefore, oxygen pressure plays a crucial role in determining electrical properties and film growth characteristics such as various microstructural defects and crystallization. Inside, the microstructure and crystallinity of the Cr-doped $SrZrO_3$ film by oxygen pressure were strong effects on the set, reset switching voltage of the Cr-doped $SrZrO_3$. The bistable switching is related to the defects and controls their number and structure. Therefore, the relation of defects generated and resistive switching behavior by oxygen pressure change will be discussed. We found that deposition conditions and ambient oxygen pressure highly affect the switching behavior. It is suggested that the interface between the top electrode and Cr-doped $SrZrO_3$ perovskite plays an important role in the resistive switching behavior. From I-V characteristics, a typical ON state resistance of $100-200\;{\Omega}$ and a typical OFF state resistance of $1-2\;k{\Omega}$, were observed. These transition metal-doped perovskite thin films can be used for memory device applications due to their high ON/OFF ratio, simple device structure, and non-volatility.

• 한국재료학회:학술대회논문집
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• 한국재료학회 1993년도 추계 학술발표 강연 및 논문 개요집
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• pp.5-6
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• 1993

• 한국전기전자재료학회논문지
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• 제14권7호
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• pp.567-571
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• 2001

We investigated the structural and electrical properties of Ba(Zr$_{x}$Ti$_{1-x}$ )O$_3$(BZT) thin films with a mole fraction of x=0.2 and a thickness of 150 nm. BZT films were prepared on Pt/SiO$_2$/Si substrate with the various substrate temperature by a RF magnetron sputtering system. When the substrate temperature was above 50$0^{\circ}C$, we obtained multi-crystalline BZT films oriented to (110), (111), and (200) directions. As the substrate temperature increases, the films are crystallized and their dielectric constants become high. C-V characteristic curve of the film deposited at high temperature is more sensitive than that of the film deposited at low temperature. The parameters of the BZT film are as follows; the dielectric constants(dissipation factors) at 1 MHz are 95(0.021), 140(0.024), and 240(0.033) deposited at 400, 500, $600^{\circ}C$, respectively; the leakage currents at 666.7 kV/cm are 5.73, 23.5, and 72.8x10$^{-8}$ A/$\textrm{cm}^2$ fo the films deposited at 400, 500, and 600 $^{\circ}C$, respectively; the leakage currents at 666.7kV/cm are 5.73, 23.5, and 72.8x10$^{-8}$ A/$\textrm{cm}^2$ for the films deposited at 400, 500, $600^{\circ}C$, respectively. The BZT film deposited at 40$0^{\circ}C$ shows stable electrical properties, but dielectric constant for application is a little small.ll.

• The Korean Journal of Ceramics
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• 제4권3호
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• pp.199-203
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• 1998

$Pb(Zr, Ti)O_3$ (Pb:Zr:Ti=1:0.52:0.48) thin films were prepared on single crystal MgO(100) substrates by dipping-pyrolysis process using a solution of constituent metal naphthenates as starting materials. The solution was spin-coated onto substrate and the precursor films were pyrolyzed at $200^{\circ}C$ in air or at $200^{\circ}C$ in argon for 1, 2, 5 and 24h, followed by final heat treatment at $750^{\circ}C$. For all the films, highly (h00)/(00l)-oriented Pb$Pb(Zr, Ti)O_3$ thin films with smooth surfaces and crack-free were obtained, whereas thin film pyrolyzed in air for 24 h exhibited polycrystalline character. According to the pole-figure analysis, epitaxy of the product films was found to depend on pyrolysis atmosphere.

• Bulletin of the Korean Chemical Society
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• 제32권8호
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• pp.2799-2801
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• 2011

• The Korean Journal of Ceramics
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• 제6권2호
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• pp.134-137
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• 2000

Zirconia films stabilized b $Y_2O_3$, YSZ, films were deposition by metal organic chemical vapor deposition (MOCVD) onto various kind of substrates. $Y_2O_3$, $ZrO_2$and the mixtures of these two were deposited and characterized. The deposition rate, the film composition and the structure could be systematically varied through the $Y(C_{11}H_{19}O_2)_3$, Zr(O.t-$C_H_9)_4$source gas ratios and the deposition temperature. The Y/Zr ratio in YSZ film could be adjusted by controlling the ratio of $Y(C_{11}H_{19}O_2)_3$, Zr(O.t-$C_4H_9)_4$partial pressures. This is because the ratios of the deposition rates of Y and Zr atoms in $Y_2O_3$and $ZrO_2$films to those in YSZ films, Ф, are constant irrespective of the input gas concentration. However, the Y/Zr ratio was found to be smaller than that estimated based on the deposition rates of un-mixed $Y_2O_3$and $ZrO_2$films. This is because the Фs of Y and Zr atoms are not equal. The activation energy of $Y_2O_3$component in YSZ films was similar to that of $ZrO_2$component in YSZ films. These YSZ values were more than 4 times larger than those of un-mixed $Y_2O_3$or $ZrO_2$films.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.547-549
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• 2001

The dielectric constants and dielectric losses of ZrTiO$_4$thin films deposited by DC magnetron reactive sputtering were investigated. The paraelectric properties were measured in the 100kHz range. As the deposition temperature increased (up to 67$0^{\circ}C$), the dielectric losses (tan$\delta$) decreased (down to 0.017$\pm$0.007), while the dielectric constants ($\varepsilon$) were in the range of 35$\pm$7. Post annealing at 80$0^{\circ}C$ in oxygen for 2h reduced tan$\delta$ down to 0.005$\pm$0.001, higher than those of well-sintered bulk ZrTiO$_4$.

• 한국전기전자재료학회논문지
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• 제11권10호
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• pp.866-870
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• 1998

PLZT thin films were fabricated with different Zr/Ti ratios by pulsed laser deposition. PLZT films deposited on Pt/Ti/SiO$_2$/Si substrate. This PLZT thin films of 5000$\AA$ thickness were crystallized at $600^{\circ}C$, $O_2$ pressure 200m Torr. 2/55/45 PLZT thin film showed a maximum dielectric constant value of $\varepsilon$\ulcorner=1550 and dielectric loss was 0.03 at 10kHz. At 2/70/30 PLZT thin film, coercive field and remnant polarization was respectively 19[kV/cm], 8[$\mu$C/$\textrm{cm}^2$]. Raman spectroscopy results showed that the bands of spectra became broader as the amount of Zr mol% increased and two crystal phase coexisted at 2/55/45 PLZT film. Raman spectroscopy was useful for crystal structure analysis of PLZT thin films.