• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(2)
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• pp.221-224
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• 2000

We have successfully demonstrated metal-ferroel-ectric-insulator-semiconductor (MFIS) devices using Al/LiNbO$_{3}$/SiN/Si structure. The SiN thin films were made into metal -insulator- semiconductor (MIS) devices by thermal evaporation of aluminum source in a dot away on the surface. The interface property of MFIS from 1MHz & quasistatic C-V is good and the memory window width is about 1.5V at 0.2V/s signal voltage sweep rate. The gate leakage current density of MFIS capacitors using a aluminum electrode showed the least value of 1x10$^{-8}$ A/$\textrm{cm}^2$ order at the electric field of 300㎸/cm. And the XRD patterns shows the probability of applications of LN for MFIS devices for FeRAMs on amorphous SiN buffer layer.

• 한국전기전자재료학회논문지
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• 제17권1호
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• pp.7-15
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• 2004

The ferroelectric SBT thin films as a material of capacitors for non-volatile FRAMs have some problems that its remanent polarization value is relatively low and the crystallization temperature is quite high abovc 80$0^{\circ}C$. Therefore, in this paper, SBTN solution with S $r_{0.9}$B $i_{2.1}$T $a_{1.8}$N $b_{0.2}$$O_{9}$ composition was synthesized by sol-gel method. Sr(O $C_2$ $H_{5}$)$_2$, Bi(TMHD)$_3$, Ta(O $C_2$ $H_{5}$)$_{5}$and Nb(O $C_2$ $H_{5}$)$_{5}$ were used as precursors, which were dissolved in 2-methoxyethanol. SBTN thin films with 200 nm thickness were deposited on Pt/Ti $O_2$/ $SiO_2$/Si substrates by spin-coating. UV-irradiation in a power of 200 W for 10 min and rapid thermal annealing in a 5-Torr-oxygen ambient at 76$0^{\circ}C$ for 60 sec were used to promote crystallization. The films were well crystallized and fine-grained after annealing at $650^{\circ}C$ in oxygen ambient. The electrical characteristics of 2Pr=11.94 $\mu$C/$\textrm{cm}^2$, Ps＋/Pr＋=0.54 at the applied voltage of 5 V were obtained for a 200-nm-thick SBTN films. This results show that 2Pr values of the UV irradiated and rapid thermal annealed SBTN thin films at the applied voltage of 5 V were about 57% higher than those of no additional processed SBTN thin films. thin films.lms.s.s.

• Transactions on Electrical and Electronic Materials
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• 제8권4호
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• pp.153-156
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• 2007

Structural and electrical properties of the fully crystallized-bismuth magnesium niobate ($Bi_2Mg_{2/3}Nb_{4/3}O_7$, BMN) films with 15 mol% excess bismuth deposited on Pt bottom electrode by pulsed laser deposition are characterized for various deposition temperatures. The BMN films were crystallized with a monoclinic structure from $300^{\circ}C$ and the surface roughness slightly decreases with increasing deposition temperature. The capacitance density of the films increases with increasing deposition temperature and especially, films deposited at $400^{\circ}C$ exhibit a capacitance density of approximately $620nF/cm^2$. The crystallized BMN films with approximately 170 nm thickness exhibit breakdown strength above 600 kV/cm (${\leq}10V$) irrespective of deposition temperature and a leakage current density of approximately $2{\times}10^{-8}A/cm^2$ at 590kV/cm (at 10 V).

• 한국진공학회지
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• 제7권1호
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• pp.17-23
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• 1998

RF magnetron co-sputtering법으로 PFN[$Pb(Fe_{0.5}Nb_{0.5}O_3(PFN)$]박막을 제조한 후 급속 열처리(rapid thermal annealing, RTA)하여 XRD(s-ray diffractometer)를 통한 박막의 상변 태 및 전기적 특성에 대하여 연구하였다. $SiO_2$/Si, ITO/glass, 및 Pt/Ti/$SiO_2$/Si기판에 PFN 박막을 증착시켰다. 기판의 변화에 따른 증착된 PFN박막의 조성변화는 관찰할 수 없었다. ITO/glass기판을 사용한 경우와 $SiO_2$/Si기판을 사용하여 증착시킨 PFN박막의 결정구조를 분석한 결과 ITO/glass기판에 증착한 시편이 perovskite상으로의 결정화가 더욱 우세하였다. 이는$SiO_2$기판의 경우 Pb의 확산에 의해 결정화가 잘 되지 못하기 때문이다. Pt/Ti/$SiO_2$/Si 기판 위에 증착시킨 PFN박막의 경우 perovskite상과 pyrochlore상이 공존하였다. Perovskite 상으로의 상변태에 대한 중요한 변수로는 열처리 온도와 Pb의 함량인 것이 확인되었으며, Pb의 함량이 화학양론적 조성비에 비해 5-10%정도 과량일수록 perovskite상으로의 상변태 온도가 낮아지고 상전이 정도가 향상되는 것으로 나타났으며, 급속 열처리 후 XRD를 이용 한 결정성 분석결과를 통해 결정한 perovskite상으로의 상전이 최저온도는 $500^{\circ}C$였다. Pb/(Fe+Nb)의 조성비가 1.17인 경우의 박막을 질소 분위기 하에서 $600^{\circ}C$로 30초간 급속열 처리 하였을 때 낮은 누설 전류 값과 1kHz에서 88의 유전 상수 값, 2.0$\mu$C/$\textrm{cm}^2$의 잔류 분극 값과 144kV/cm의 항전계 값을 얻었다.

• 한국자기학회지
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• 제14권4호
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• pp.120-126
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• 2004

DC 마그네트론 스파터링 방법으로 제작한 F $e_{84}$ N $b_{16}$ (wt.%) 박막의 온도변화에 따른 자기적 특성을 강자성 공명 흡수선의 거동을 통하여 고찰했다 모든 온도영역에서 다수의 체적 모드 스핀파와 한 개 또는 두 개의 표면 모드가 관측되었는데, 이와 같은 현상은 시편 양면의 표면 자기 이방성이 0보다 작은 경우에 나타나는 특성이다. 113-293K 온도영역에서 포화자화는 Bloch의 $T^{2}$ 3/ 법칙과 부합되는 모습을 보였으며, 분광학적 분리인자는 온도변화에 비교적 작은 변화 폭을 보였다 233-293K 온도구간에서 기판과 접하는 시편면의 표면 자기 이방성 상수 Ksl는 온도감소에 따라 그 갈이 비교적 큰 폭으로 증가하는 특성을 나타냈다. 그리고 공기와 접하는 시편면의 표면 자기 이방성 상수 $K_{sl}$ 은 상온에서 -0.322 erg/$\textrm{cm}^2$인 값을 보이다가, 온도가 253 K로 내려가면 -0.394 erg/$\textrm{cm}^2$로 감소한 후, 그 이하의 온도영역에서는 온도에 비교적 둔감한 특성을 보였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.171-171
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• 2012

Neutral beam assisted chemical vapor deposition (NBa-CVD) process has been developed as a nove,l room temperature deposition process for the light-soaking free nano-crystalline silicon (nc-Si) thin films including intrinsic and n-type doped thin film. During formation of nc-Si thin films by the NBa-CVD process with silicon reflector at room temperature, the energetic particles enhance doping efficiency and crystalline phase in nc-Si thin films without additional heating at substrate. The effects of incident NB energy controlled by the reflector bias have been confirmed by Raman spectra analysis. Additionally, TEM images show uniform nc-Si grains which imbedded amorphous phase without incubation layer. The nc-Si films by the NBa-CVD are hardly degenerated by light soaking; the degradations of photoconductivity were just a few percents before and after light irradiation.

• 한국전기전자재료학회논문지
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• 제16권9호
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• pp.795-800
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• 2003

The dielectric and piezoelectric properties of the xPb(A $l_{0.5}$N $b_{0.5}$) $O_3$-(1-x)Pb(Z $r_{0.52}$ $Ti_{0.48}$) $O_3$ [xPAN-(1-x)PZT] thin films by pulsed laser deposition (PLD) were investigated as a function of PAN contents. The effect of texture on dielectric and piezoelectric properties of the 0.05PAN-0.95PZT thin films having the highest piezoelectric constant( $d_{33}$) was studied more precisely. For 0$\leq$x$\leq$0.15 compositions in xPAN-(1-x)PZT thin films, the well-developed perovskite phase with (111) preferred orientation was obtained at the deposition temperature of 50$0^{\circ}C$. With increasing PAN content, remanent polarization and coercive field decreased. The dielectric constant increased with an increase of PAN content until it reached 1450 at $\chi$= 0.05, and then decreased for higher PAN content. The maximum points of dielectric constant coincides with the maximum points of the piezoelectric constant $d_{33}$.33/.33/././.

• 열처리공학회지
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• 제22권5호
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• pp.290-297
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• 2009

In case of using Asymmetric Bipolar Pulsed DC (ABPD) power generator, thin film is efficiently deposited as ions are getting higher energy by suppressing target poisoning and electric arc. In this article, the mechanical properties of CNx thin films deposited on the STS 316L were compared with DC and ABPD power generators. The CNx thin films deposited with ABPD clearly improved wear resistance by higher ratio of sp3CN as compared with DC. Nb interlayer affected to increase the value of 10N of adhesion between CNx thin films and substrate. But, CNx thin films deposited with ABPD couldn't endure to wear load and decreased wear resistance as the films were too thinner than substrate. Nevertheless the higher substrate bias energy applied to perform the dense films, it wasn't shown benefits about the wear properties from DC sputtering. But, in case of using ABPD sputtering, the wear resistance was largely improved without changing morphology despite of thin films.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2005년도 추계종합학술대회
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• pp.1265-1268
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• 2005

In this study, the synthesis and semiconducting properties of cation and defect-doped $KTaO_3$ film is reported. $KTaO_3$ is an important material for optoelectronic and tunable microwave applications. It is an incipient ferroelectric with a cubic structure that becomes ferroelectric when doped with Nb. While numerous studies have investigated the thin-film growth of semiconducting perovskites, little is reported about semiconducting $KTaO_3$ thin films. In this work, the films were grown on (001) MgO single crystal substrates using pulsed-laser deposition. Semiconducting behavior is achieved by inducing oxygen vacancies in the $KTaO_3$ lattice via growth in a hydrogen atmosphere. The resistivity of semiconducting $KTaO_3:Ca$ films was as low as 10cm, and n-type semiconducting behavior was indicated. Hall mobility and carrier concentration were $0.27cm^2/Vs$ and $3.21018cm^{-3}$, respectively. Crystallinity and microstructure of the $KTaO_3:Ca$ films were examined using X-ray diffraction and field-emission scanning microscopy.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.981-982
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• 2006

In this study, the synthesis and semiconducting properties of cation and defect-doped KTaO3 film is reported. KTaO3is an important material for optoelectronic and tunable microwave applications. It is an incipient ferroelectric with a cubic structure that becomes ferroelectric when doped with Nb. the films were grown on (001) MgO single crystal substrates using pulsed-laser deposition. Semiconducting behavior is achieved by inducing oxygen vacancies in the KTaO3 lattice via growth in a hydrogen atmosphere. The resistivity of semiconducting KTaO3:Ca films was as low as 10cm, and n-type semiconducting behavior was indicated. Hall mobility and carrier concentration were 0.27 cm2/Vs and 3.21018cm-3.