• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.171-171
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• 2007

Dysprosium-doped bismuth titanate (BDT) thin films were successfully deposited on Pt(111)/Ti/$SiO_2$/Si(100) substrates by liquid delivery MOCVD process and their structural and ferroelectric properties were characterized. Fabricated BDT thin films were found to be random orientations, which were confirmed by X-ray diffraction experiment and scanning electron microscope analysis. The crystallinity of the BDT films was improved and the average grain size increased as the crystallization temperature increased from 600 to $720^{\circ}C$ at an interval of $40^{\circ}C$. The BDT thin film annealed at $720^{\circ}C$ showed a large remanent polarization (2Pr) of $52.27\;{\mu}C/cm^2$ at an applied voltage of 5V. The BDT thin film exhibits a good fatigue resistance up to $1.0{\times}10^{11}$ switching cycles at a frequency of 1 MHz with applied pulse of ${\pm}5\;V$. These results indicate that the randomly oriented BDT thin film is a promising candidate among ferroelectric materials useti비 in lead-free nonvolatile ferroelectric random access memory applications.

• 한국세라믹학회지
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• 제40권1호
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• pp.46-51
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• 2003

Liquid delivery MOCVD 공정으로 200nm 정도의 두께를 가진 강유전성 S $r_{0.7}$B $i_{2.1}$T $a_{2.0}$ $O_{9}$ 박막을 Pt/Ti/ $SiO_2$/Si 기판 위에 증착하였다. 본 실험에서는 Sr(TMHD)$_2$.pmdeta, Bi(ph)$_3$ 그리고 Ta( $O^{i}$ Pr)$_4$(TMHD)를 출발 물질로 사용하였으며 n-butyl acetate와 pentamethyldiethylenetriamine를 용매로 사용하였다. 이 실험의 기판 온도와 압력 조건은 각각 57$0^{\circ}C$와 5 Torr였다. 78$0^{\circ}C$에서 열처리한 SBT 박막의 3V와 5V 인가 전압하에서의 잔류분극값은 각각 7.247 $\mu$C/$\textrm{cm}^2$와 8.485 $\mu$C/$\textrm{cm}^2$이었다.다.다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 센서 박막재료 반도체 세라믹
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• pp.111-115
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• 2003

200nm 정도의 두께를 가진 SBT 박막이 liquid delivery MOCVD 공정에 의해 (111) oriented Pt/Ti/$SiO_2$/Si 기판 위에 증착되었다 이 실험에서는 $Sr(TMHD)_2$tetraglyme, $Bi(ph)_3$ 그리고 $Ta(O^iPr)_4$(TMHD)를 출발 물질로 사용하였다. Sr 출발 물질의 열적 안정화를 위해서 adduct로 tetraglyme를 사용하여 실험하였고 유기 용매로는 n-butyl acetate를 사용하였다 Substrate temperature와 reactor pressure는 각각 $570^{\circ}C$와 5Torr로 유지시켰다. 또한 vaporizer의 용도는 $190-200^{\circ}C$, 그리고 delivery line 의 온도는 vaporizer 보다 높게 유지 $(220-230^{\circ}C)$하여 출발 용액을 분당 0.1ml로 50분간 주입하였다. 수송가스로 Ar, 산화제로 $O_2$ 가스를 사용하였다. 제조한 SBT 박막은 $750^{\circ}C$에서 열처리한 후 인가전압 3V와 5V에서 $2P_r$값이 각각 6.47, $8.98{\mu}C/cm^2$이었으며, $2E_c$값은 인가전압 3V와 5V에서 각각 2.05, 2.31V이었다 그리고 $800^{\circ}C$에서는$750^{\circ}C$에서 열처리한 SBT 박막보다 다소 우수한 이력특성을 나타내어 $2P_r$ 값은 인가전압 3V와 5V에서 각각 7.59, $10.18{\mu}C/cm^2$ 이었으며, $2E_c$값은 인가 전압 3V와 5V에서 각각 2.00, 2.21V 이었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2004년도 제26회 학술발표회 초록집
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• pp.163-163
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• 2004

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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• pp.39-40
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• 2005

Ferroelectric Eu-substituted $Bi_4Ti_3O_{12}$ (BET) thin films with a thickness of 200 nm were deposited on Pt(111)/Ti/SiO$_2$/Si(100) substrate by means of the liquid delivery MOCVD system and annealed at several temperatures in an oxygen atmosphere. At annealing temperature above $600^{\circ}C$, the microstructure of layered perovskite phase was observed. The remanent polarization of these films increased with increase in annealing temperature. The remanent polarization values ($2P_r$) of the BET thin films annealed at $720^{\circ}C$ were $37.71{\mu}C/cm^2$ at an applied voltage of 5 V.

• 한국전기화학회:학술대회논문집
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• 한국전기화학회 2002년도 춘계총회 및 학술발표회
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• pp.48-48
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• 2002

• 한국전기화학회:학술대회논문집
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• 한국전기화학회 2001년도 추계총회 및 학술발표회
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• pp.38-38
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• 2001

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제51권9호
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• pp.423-429
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• 2002

RuOx thin films were fabricated by the method of liquid delivery MOCVD using Ru(C$_{8}$ $H_{13}$ $O_2$)$_3$ as the precursor and their thermal effects and conductivity were investigated. Ru films deposited at 25$0^{\circ}C$ were annealed at $650^{\circ}C$ for 1min with Ar, $N_2$ or N $H_3$ ambient. The changes of the micro-structure, the surface morphology and the electrical resistivity of the Ru films after annealing were studied. Ar gas was more effective than $N_2$ and N $H_3$ gases as an ambient gas for the post annealing of the Ru films, because of smaller resistivity and denser grains. The X-ray diffraction and X-ray photoelectron spectroscopy results indicate that the Ru $O_2$ phase and the silicidation are not observed regardless of the ambient gases. The minimum resistivity of the Ru film is found to have the value of 26.35 $\mu$Ω-cm in Ar ambient. Voids were formed at Ru/TiN interface of the Ru layer after annea1ing in $N_2$ ambient. The $N_2$ gas generated due to the oxidation of the TiN layer accumulated at the Ru/TiN interface, forming bubbles; consequently, the stacked film may peel off the Ru/TiN interface.e.

• 한국세라믹학회지
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• 제44권8호
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• pp.403-406
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• 2007

Ferroelectric Ce-doped $Bi_4Ti_3O_{12}$ (BCT) thin films were deposited by liquid delivery metal organic chemical vapor deposition (MOCVD) onto a $Pt(111)/Ti/SiO_2/Si(100)$ substrate. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to identify the crystal structure, the surface, and the cross-section morphology of the deposited ferroelectric flims. After annealing above $640^{\circ}C$, the BCT films exhibited a polycrystalline structure with preferred (001) and (117) orientations. The BCT lam capacitor with a top Pt electrode showed a large remnant polarization ($2P_r$) of $44.56{\mu}C/cm^2$ at an applied voltage of 5 V and exhibited fatigue-free behavior up to $1.0{\times}10^{11}$ switching cycles at a frequency of 1 MHz. This study clearly reveals that BCT thin film has potential for application in non-volatile ferroelectric random access memories and dynamic random access memories.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2002년도 제23회 학술발표회 초록집
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• pp.150-150
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• 2002