• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1434-1436
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• 1996

In this study, ferroelectric $PbTiO_3$ thin films were deposited on the Pt/$SiO_2$/Si substrate by Sol-Gel method. $PbTiO_3$ stock solution was made and spin-cooled at 4000[rpm] for 30[sec.]. Coated specimens were dried at $400[^{\circ}C]$ for 10[min.] and then annealed at $500{\sim}800[^{\circ}C]$ for 1 hour. Annealing temperature were examined to optimize micro structural and dielectric properties of the films. The ferroelectric perovskite phase was observed in the file annealed at $700[^{\circ}C]$ for 1 hour. In the case of $PbTiO_3$ thin films annealed at $700[^{\circ}C]$ for hour, dielectric constant and dielectric loss showed the good value of 324, 2.0[%], respectively.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 일렉트렛트 및 응용기술
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• pp.58-62
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• 2002

Pb($Zr_{0.52}Ti_{0.48}$)$O_3$ (PZT) thin films deposited on the Pt/Ti and Ru/$RuO_2$ bottom electrode by rf magnetron sputtering methode. Ru/$RuO_2$ bottom electrode deposited on the p-type wafer as Ru thickness by in-situ process. Our results show that all PZT films indicated perovskite polycrystalline structure with perferred orientation (110) and no pyrochlore phase is observed. A well-fabricated $RuO_2$/PZT/Ru(100nm)/$RUO_2$ capacitor showed a leakage current density in the order of $2.13{\times}10^{-7}A/cm^2$ as 100 kV/cm, a remanent polarization of 7.20 ${\mu}C/cm^2$, and a coercive field of 58.37 kV/cm. The results show that the new Ru/$RuO_2$ bottom electrodes are expected to reduce the degradation ferroelectric fatigue and excellent ferroelectric properties.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.71-74
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• 2000

Pt/Pb$TiO_3$/$SrTiO_3$/p-Si films were prepared by metallo-organic solution deposition(M0SD) method and investigated its structure and ferroelectric properties. Crystallinity of specimen as a funtions of post annealing temperature and the thickness of $SrTiO_3$(STO) buffer layer was studied using XRD and AFM. Based on C-V and P-E curve, $PbTiO_3$(PTO) capacitors showed good ferroelectric hysteresis arising from the polarization switching properties. When the thickness of ST0 buffer layer between PTO and Si substrate was 260 nrn and the post annealing temperature was $650^{\circ}C$, it was showed that production of the pyrochlore phase due to interdiffusion of Si into FTO was prevented. The dielectric constant of FTO thin films calculated from a maximum Cma in the accumulation region was 180 and the dielectric loss was 0.30 at 100 kHz frequency. The memory window in the C-V curve is 1.6V at a gate voltage of 5V.

• 한국전기전자재료학회논문지
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• 제11권12호
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• pp.1108-1114
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• 1998

$BaTiO_3$ thin films preferred c-axis orientation for the potential application of ferroelectric memory devices were deposited on silicon substrates(100) by RF sputtering and annealed at 800 and 900[$^{\circ}C$] in air. The BT(100)/BT(110) peak ratio of the sputtered sample was decreased with post-annealing in air. According to increasing with annealing temperature and time, the peak ratio of BT(100)/BT(110) was decreased and the surface density of thin film was high. Dielectric characteristics of $BaTiO_3$ thin film was measured as a function of annealing temperature and frequency. The dielectric constants were increased with annealing and decreased with frequency by space charge polarization and dipole polarization below 600[kHz]. The remanent polarization and coercive field in P-E hysteresis loop of $BaTiO_3$thin film were increased with the annealing temperature in air. The remanent polarization and coercive filed annealed at 800[$^{\circ}C$] for 1hr were 1.2[$\mu$C/$cm^2$] and 200[kV/cm]

• Transactions on Electrical and Electronic Materials
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• 제14권3호
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• pp.130-132
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• 2013

$Bi_{3.25}La_{0.75}Ti_3O_{12}$(BLT) thin films were prepared on the Pt(150 nm)/Ti(50 nm)/$SiO_2$/Si substrate using the rf magnetron sputtering method. The BLT thin films were annealed at temperatures ranging from $600^{\circ}C$ to $750^{\circ}C$ using the rapid thermal annealing. The structure and surface morphology of the thin films were characterized by x-ray diffraction and field emission scanning electron microscopy. The hysteresis loop of the BLT thin films showed that the remanent polarization (2Pr) of the film annealed at $700^{\circ}C$ was 10.92 ${\mu}C/cm^2$. The fatigue characteristic of the BLT thin film annealed at $700^{\circ}C$ was shown change polarization up to $1.2{\times}10^9$ switching cycles. We confirmed the excellent remnant polarization (Pr) and fatigue properties compared with other fabrication methods and suggested a good method for BLT thin films fabrications.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1301-1302
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• 2007

The multilayered $Pb_{1.1}(Zr_{0.4}Ti_{0.6})O_{3}$/$Pb_{1.1}(Zr_{0.6}Ti_{0.4})O_{3}/Pb_{1.1}(Zr_{0.4}Ti_{0.6})O_{3}$[PZT(4060)/(6040)/(4060)] thin films were deposited by RF sputtering method on the Pt/TiO2/SiO2/Si substrate. We investigated the effects of deposition conditions on the structural and electrical properties of the multilayered PZT thin films. All the multilayered PZT thin films showed dense and homogeneous structure without the presence of the rosette structure. The dielectric properties such as dielectric constant, loss, remanent polarization of the multilayered PZT thin film were superior to those of single composition PZT(4060) and PZT(6040) films, and those values for the multilayered PZT(10/20/10) thin film were 903, 1.01% and $25.60{\mu}C/cm^2$. This study suggests that the design of the multilayered PZT thin films capacitor with tetragonal and rhombohedral phase should be an effective method to enhance the dielectric and ferroelectric performance in devices.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.709-712
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• 2001

The effects of post annealing temperature by the Rapid Thermal Annealing(RTA) on the electrical properties of Pb(Zr,Ti)O$_3$(PZT) thin film were investigated. Analyses by the RTA treatments reveled that the leakage current of PZT thin films strongly depend on heating temperature and time. It was found that leakage current properties of PZT capacitor were changed by heating temperature during the RTA annealing. On Pt/Ti/Si substrates, PZT films are deposited at 350 $^{\circ}C$ by rf magnetron sputtering. The X-ray diffusion (XRD) was confirmed the formation of PZT thin film. Leakage current characteristics were improved with decreasing the post annealing temperature of PZT thin film. RTA annealed film on the 700$^{\circ}C$ shows ferroelectric and electrical properties with a remanent polarization of 12.4${\mu}$C/$\textrm{cm}^2$ coercive field of 117kV/cm, leakage current J= 6.2${\times}$10$\^$-6/ A/$\textrm{cm}^2$

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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• pp.118-121
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• 1999

PLZT thin films were fabricated with different energy density by pulsed laser deposition. PLZT films deposited on Pt/Ti/SiO$_2$/Sr substrate. This PLZT thin films of 5000$\AA$ thickness were crystallized at $600^{\circ}C$, 200mTorr $O_2$ pressure for 2 J/$\textrm{cm}^2$ laser energy density. 14/50/50 PLZT thin film showed a maximum dielectric constant value of $\varepsilon$$_{r}$=1289.9 P-E hysteresis loop of 14/ 50/50 PLZT thin film was slim ferroelectric. Leakage current density of 14/50/50 PLZT thin film was 10/ sup -7/=A/$\textrm{cm}^2$.>.

• 한국진공학회지
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• 제9권2호
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• pp.136-143
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• 2000

RF magnetron sputtering법으로 $SrBi_2Ta_2O_9$ (SBT)박막을 상온에서 p-type Si(100) 기판위에 증착하여 DRO 강유전체 메모리(destructive read out ferroelectric random access memory)에 사용되는 강유전체막으로 Pt/SBT/Pt/Ti/$SiO_2$/Si (MFM)구조의 응용가능성을 확인하였다. 구조적인 특징들이 열처리 시간의 변화와 Ar/$O_2$의 가스 유량비의 변화에 따라서 XRD(x-ray diffractometer)에 의해 관찰되었으며 표면 특성은 FE-SEM(field emission scanning electron microscopy)에 의해서 관찰하고 박막의 전기적 특성들은 P-V(polarization-voltage measurement)와 I-V(current-voltage measurement)를 사용하여 관찰하였다. 스퍼터링 증착시 Ar/$O_2$의 가스 유량비는 1:4에서 4:1까지 변화 시켰고 SBT박막은 상온에서 증착시켰다. XRD 측정시 박막들은 SBT의 (105), (110) peak들을 나타내었다. 상온에서 증착시킨 박막은 1시간, 2시간 동안 산소 분위기에서 $800^{\circ}C$ 열처리를 하여 결정화 시켰다. SBT 박막의 P-V곡선은 이력 곡선의 모양을 갖추었으며 비대칭적인 강유전체 특성을 나타내었다. Ar/$O_2$ 가스유량비가 1 : 1, 2 : 1인 경우에 박막의 누설 전류밀도 값이 제일 좋았으며, 그 값은 3V 5V 7V에서 각각 $3.11\times10^{-8} \textrm{A/cm}^2$, $5\times10^{-8}\textrm{A/cm}^2$, $7\times10^{-8}\textrm{A/cm}^2$ 이었다. 열처리 시간을 2시간으로 증가시킨 후, 그들의 전기적 특성과 결정화특성이 개선됨을 확인하였다. AES 분석 및 EPMA분석으로 SBT박막의 깊이 분포 및 조성을 확인하였다.

• 한국결정성장학회지
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• 제10권2호
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• pp.140-144
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• 2000

($Pb_{0.91}$$La_{0.09}$)($Zr_{0.65}$$Ti_{0.35}$)$O_3$ thin films were prepared on ITO-coated glass by spin-coating. As $Pb_{0.9}$$La_{0.1}$)$TiO_3$ thin films were used as seeding layers, formation temperature of perovskite was reduced and theUrosette" structure was disappeared. PLZT thin films with a seeding layer of 40 nm thick showed a (100) preferred orientation and better dielectric and ferroelectric properties.ties.