• 대한전자공학회논문지SD
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• 제38권5호
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• pp.375-381
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• 2001

디바이스의 크기가 0.25㎛이하로 축소됨에 따라 DRAM(Dynamic Random Access Memory) 제조업체들은 칩 크기를 줄이고 지역적인 배선으로 사용하기 위해서 기존의 텅스텐-폴리사이드 비트-선에서 텅스텐 비트-선으로 대체하고 있다. 본 논문에서는 다양한 RTP 온도와 추가 이온주입을 사용하여 낮은 저항을 갖는 텅스텐 비트-선 제조 공정에 대해 다루었다. 그 결과 텅스텐 비트선 저항에 중요한 메계변수는 RTP Anneal 온도와 BF₂ 이온 주입 도펀트임을 알 수 있었다. 이러한 텅스텐 비트-선 공정은 고밀도 칩 구현에 중요한 기술이 된다.

• Current Optics and Photonics
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• 제2권1호
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• pp.79-84
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• 2018

We present a novel and simple method to enable spatially selective $ZnAl_2O_4$ nanocrystal formation on the surface of $B_2O_3$-$Al_2O_3$-ZnO-CaO-$K_2O$ glass by employing localized laser heating. Optimized precipitation of glass-ceramics containing nanocrystals doped with $Eu^{3+}$ and $Yb^{3+}$ ions was performed by controlling $CO_2$ laser power and scan speed. Micro-x-ray diffraction and transmission electron microscopy revealed the mean size and morphology of nanocrystals, and energy dispersive x-ray spectroscopy showed the lateral distribution of elements in the imaged area. Laser power and scan speed controled annealing temperature for crystalization in the range of 1.4-1.8 W and 0.01-0.3 mm/s, and changed the size of nanocrystals and distribution of dopant ions. We also report more than 20 times enhanced downshift visible emission under ultraviolet excitation, and 3 times increased upconversion emission from $Eu^{3+}$ ions assisted by efficient sensitizer $Yb^{3+}$ ions in nanocrystals under 980 nm excitation. The confocal microscope revealed the depth profile of $Eu^{3+}$ ions by showing their emission intensity variation.

• ETRI Journal
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• 제38권2호
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• pp.260-264
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• 2016

We report on highly efficient blue, orange, and white phosphorescent organic light-emitting diodes consisting only two organic layers. Hole transporting 4, 4,' 4"-tris (N-carbazolyl)triphenylamine (TcTa) and electron transporting 2-(diphenylphosphoryl) spirofluorene (SPPO1) are used as an emitting host for orange light-emitting bis(3-benzothiazol-2-yl-9-ethyl-9H-carbazolato) (acetoacetonate) iridium ((btc)2(acac)Ir) and blue light-emitting iridium(III)bis(4,6-difluorophenyl-pyridinato-N,C2') picolinate (FIrpic) dopant, respectively. Combining these two orange and blue light-emitting layers, we successfully demonstrate highly efficient white PHOLEDs while maintaining Commission internationale de l'eclairage coordinates of (x = 0.373, y = 0.443). Accordingly, we achieve a maximum external quantum, current, and power efficiencies of 12.9%, 30.3 cd/A, and 30.0 lm/W without out-coupling enhancement.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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• pp.460-463
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• 2002

$MoO_3$ thin films were deposited on electrode and heater screen-printed alumina substrates in $O_2$ atmosphere by RF reactive sputtering using Molybdenum metal target. The deposition was performed at $300^{\circ}C$ with 350W of a forward power in an $Ar-O_2$ atmosphere. The working pressure was maintained at $3{\times}10^{-2}mtorr$ and all deposited films were annealed at $500^{\circ}C$ for 5hours. To investigate gas sensing characteristics of the addition doped $MoO_3$ thin film, Co, Ni and Pt were used as adding dopants. The sensing properties were investigated in tenn of gas concentration under exposure of reducing gases such as $H_2$, $NH_3$ and CO at optimum working temperature. Co-doped $MoO_3$ thin film shows the maximum 46.8% of sensitivity in $NH_3$ and Ni-doped $MoO_3$ thin film exhibits 49.7% of sensitivity in $H_2$.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 C
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• pp.1352-1354
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• 1997

Transparent conductive thin films have found many application in many active and passive electronic and opto-electronic devices as like flat Panel display electrode and window heat mirror, etc. Low resistivity and high transmittance of this films can be obtained by controlling deposition parameters, which are oxygen partial Pressure, substrate temperature and dopant concentration. In this study, We prepared non-stoichiometric and Sb-doped thin films of tin dioxide by reactive DC magnetron sputtering technology. The lowest resistivity of about $3.0{\times}10^{-3}\;{\Omega}cm$ and 80% transmittance in the visible light region have heed obtained at optimal deposition condition.

• 한국표면공학회지
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• 제30권6호
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• pp.406-411
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• 1997

Transparent conductive thin films have found many applications in active and passive electronic and opto-electronic devices such as flat panel display electrode, solar cell electrode and window heat mirror, etc. Low resistivity and high transmittance of these films can beotained by controlling deposition parameters which are oxygen partial pressure, substrate temperature and dopant concentration. In this study, non-stoichiometric and Sb-doped thin electrical properties of undoped films have been degraded with increase of substrate temperature and optical properties have been improved in Sb-doped films. The resistivity of $2.5\times10^{-3}\Omega\textrm{cm}$,/TEX>, average transmittance of 80% and sheet resistance of 130$\Omega$/$\square$ at thickess of 2000 $\AA$ could be obrained at optmal condimal conditions which were at $400^{\circ}C$ of substrate temperature, 58% of oxygen partial pressure and 5% of Sb doping concentration.

• 전자공학회논문지A
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• 제33A권3호
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• pp.126-134
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• 1996

Tungsten silicide films were deposited on the phosphorus-doped poly-Si/SiO$_{2}$/Si-substrates by LPCVD (low pressue chemical vapor deposition). The formation and various properties of tungsten silicide processed by furnace annealing in N$_{2}$ ambient were evaluated by using XRD. AFM, 4-point probe and SEM. And the redistribution of phosphorus atoms has been observed by SIMS. The crystal structure of the as-deposited tungsten silicide films were transformed from the hexagonal to the tetragonal structure upon annealing at 550.deg. C. The surface roughness of tungsten polycide films were found to very smoothly upon annelaing at 850.deg. C and low phosphorus concentration in polysilicon layer. The sheet resistance of tungsten polycide low phosphorus concentration in polysilicon layer. The sheet resistance of tungsten polycide films are measured to be 2.4 .ohm./ㅁafter furnace annealing at 1100.deg. C, 30min. It was found that the sheet resistance of tungsten polycide films upon annealing above 1050.deg. C were independant on the phosphorus concentration of polysilicon layer and furnace annealing times. An out-diffusion of phosphorus impurity through tungsten silicide film after annealing in $O_{2}$ ambient revealed a remarkably low content of dopant by oxide capping.

• 한국전기전자재료학회논문지
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• 제16권8호
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• pp.705-710
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• 2003

MoO$_3$thin films were deposited on electrode of alumina substrates in $O_2$atmosphere by RF reactive sputtering using molybdenum metal target. The deposition was performed at 30$0^{\circ}C$ with 350 W of a forward power in an Ar-O$_2$atmosphere. The working pressure was maintained at 3$\times$10$^{-2}$ torr and all deposited films were annealed at 50$0^{\circ}C$ for 5 hours. The surface morphology of films was observed by using a SEM and crystalline phases were analyzed by using a XRD. To investigate gas sensing characteristics of the doped MoO$_3$thin film, Co, Ni and Pt were used as dopants. The sensing properties were investigated in term of gas concentration under exposure of reducing gases such as H$_2$, NH$_3$and CO at optimum working temperature. Co-doped MoO3 thin film shows the maximum 46.8 % of sensitivity in NH$_3$ and Ni-doped MoO$_3$thin film exhibits 49.7 % of sensitivity in H$_2$.

• Journal of Ceramic Processing Research
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• 제13권spc2호
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• pp.394-397
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• 2012

In this work, we studied the influence of the dopant elements concentration on the properties of SnO2 thin films deposited by pulsed laser deposition. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Hall effect measurement and UV-Vis studies were performed to characterize the deposited films. XRD results showed that the films had polycrystalline nature with tetragonal rutile structure. FE-SEM micrographs revealed that the as deposited films composed of dense microstructures with uniform grain size distribution. All the films show n-type conduction and the best transparent conductive oxide (TCO) performance was obtained on 6 wt% Sb2O5 doped SnO2 film prepared at pO2 of 60mtorr and Ts of 500 ℃. Its resitivity, optical transmittance, figure of merit are 7.8 × 10-4 Ω cm, 85% and 1.2 × 10-2 Ω-1, respectively.

• 한국재료학회지
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• 제10권8호
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• pp.525-531
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• 2000

플라즈마 화학증착법을 이용하여 Corning glass 1737 기판에 안티몬 도핑 산화주석 박막을 증착하였다. 플라즈만 화학증착시 반응변수에 따른 박막의 결정상 및 형성된 표면거칠기에 대하여 XRD와 AFM을 이용하여 검토하였다. 반응온도 $450^{\circ}C$, 유입가스비 R[$P_{SbCl}P_{{SnCl}_4}$]=1.12, r.f. power 30W에서 비교적 결정성이 뛰어난 박막을 얻을 수 있었다. 화학증착법(TCVD)에 비해 플라즈마 열화학증착법(PECVD)으로 얻은 박막의 표현형상이 보다 균일하였다. 안티몬 도핑농도가 증가할수록, 증착온고가 낮을수록, 증착두께가 작을수록 박막의 표면거칠기가 보다 감소하였다.