• 한국전기전자재료학회논문지
• /
• 제16권1호
• /
• pp.1-4
• /
• 2003

The SiH$_4$soak step is widely used to prevent the WF$_{6}$ attack to the underlayer metal using the chemical vapor deposition (CVD) method. Reduction or skipping of the SiH$_4$soak process time if lead to optimizing W-plug deposition process on via. The electrical characteristics including via resistance and the structure of W-film are affected by the time of SiH$_4$soak process. The possibility of elimination of SiH$_4$soak process is confirmed In the case of W- film grown on the stable Ti/TiN underlayer.

• 한국CDE학회논문집
• /
• 제8권3호
• /
• pp.150-156
• /
• 2003

Direct Metal Deposition (DMD) is a new additive process producing three-dimensional metal components or tools directly from CAD data, which aims to take mold making and metalworking in an entirely new direction. It is the blending of five common technologies: lasers, CAD, CAM, sensors and materials. In the resulting process, alternatively called laser cladding, an industrial laser is used to locally heat a spot on a tool-steel work piece or platform, forming a molten pool of metal. A small stream of powdered tool-steel metal is then injected into the metal pool to increase the size of the molten pool. By moving the laser beam back and forth, under CNC control, and tracing out a pattern determined by a computerized CAD design, the solid metal part is eventually built line-by-line, one layer at a time. DMD produces improved material properties in less time and at a lower cost than is possible with traditional fabrication technologies.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1999년도 추계학술대회 논문집
• /
• pp.121-124
• /
• 1999

The (Ba,Sr)TiO$_3$[BST] thin film were fabricated on the Pt/Ti/SiO$_2$/Si substrate by RF sputtering technique. The structural properties of the BST thin films were investigated with deposition time and substrate temperature by XRD. In the case of the BST thin films which has the deposition thin of 20 min, second phases and BST (111) peaks were increased with increasing the temperature of substrate. The capacitance of the BST thin film (deposition time of 20 min.) was decreased with the substrate temperature and was 1500pF with applied voltage of 1V.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1997년도 추계학술대회 논문집
• /
• pp.80-84
• /
• 1997

In this experiment, A1$_2$O$_3$ thick films were prepared by electrophoretic method using A1$_2$O$_3$ fine Powder of which composition were FA-5-500 and FA-5-900. The growth behavior of A1$_2$O$_3$ thick films were characterized as preparation conditions, such as applied voltage, deposition time and adding conditions. As a result, A1$_2$O$_3$ thick films were successfully fabricated by electrophoretic method on molybdnum plate in which etanol and distilled used were used as a solvent. Deposition conditions for good uniformity of the A1$_2$O$_3$ thick films were applied voltage of 60volts, deposition time of 2 seconds, heat treatment at 1$700^{\circ}C$ for 5 minutes.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 1984년도 제26회 수공학연구발표회논문초록집
• /
• pp.7-21
• /
• 1984

Entrainment and deposition experiments were counducted in fresh water on four groups of sediments: three well-defined sediments of uniform composition and narrow-size distribution (1 to 9 um, 10 to 50 um, and 50 to 90 um), and a fourth group which was a mixture of these three sediments. In the entrainment experiments and at a particular stress, the steady-state suspended sediment concentration of the coarse group was the lowest while the concentrations of the fine and medium groups were higher that that of the coarse group but were similar to each other. Deposition experiments generally showed an exponential decrease of suspended sediment concentration with time with the decay time being a function of particle size and applied stress.

• 한국환경보건학회지
• /
• 제32권4호
• /
• pp.359-372
• /
• 2006

In order to investigate the daily deposition characteristics of water-soluble inorganic components in airborne deposit on the Iksan, deposition samples were collected using a deposition gauge from October 16 to November 1, 2004. Deposition samples were collected using two different sampling gauges, a dry gauge and a wet gauge, respectively. To get wet the bottom of wet gauge during the sampling period, the volume of $30{\sim}50ml$ distilled ionized water was added in a wet gauge before the beginning of each deposition sampling. Deposition samples were collected twice a day and analyzed for inorganic water-soluble anions ($Cl^-,\;{NO_3}^-,\;{SO_4}^{2-}$) and cations (${NH_4}^+,\;Na^+,\;K^+,\;Mg^{2+},\;Ca^{2+}$) using ion chromatography. Qualify control and quality assurance of analytical data were checked by the data obtained from reinjection of standard solution, Dionex cross check standard solutions, and random several deposition samples, and measured data was estimated to be reliable. Considering the deposition sample volume, the sampling time, the surface area of sampling container, and the ion concentration measured, the daily deposition amounts for measured ions were calculated in $mg/m^2$. The total daily deposition amounts of all measured ions for dry and wet gauge were $7.5{\pm}2.8$ and $17.7{\pm}4.2mg/m^2$, respectively. A significant increase in deposition amount during rainfall days was observed for both wet gauge and dry gauge, having no difference of deposition amount between in wet gauge and in dry gauge. The mean deposition of all ions measured in this study were higher in wet gauge than in dry gauge because of the surface difference of the sampling container, especially for ${NH_4}^+\;and\;{SO_4}^{2-}$. The mean deposition amounts of ${NH_4}^+\;and\;{SO_4}^{2-}$ in wet gauge were found to be about 10 times and 3 times higher than those in dry gauge, while the rest of the chemical species were equal or a little higher in wet gauge than in dry gauge. Dominant species in dry gauge were ${NO_3}^-\;and\;Ca^{2+}$, accounting for 21% and 28% of the total ion deposition, whereas those in wet gauge were ${SO_4}^{2-}\;and\;{NH_4}^+$, accounting for 19% and 41% of the total ion deposition, respectively.

• 공업화학
• /
• 제10권1호
• /
• pp.98-104
• /
• 1999

본 연구에서는 ECR플라즈마 화학증착법을 이용하여 반응기내 압력의 변화에 따라 수소화된 무정형 실리콘막을 증착하고 박막내 수소의 함량과 결합구조 및 전기적 특성을 조사하였다. 일반적인 CVD에 의해 제조된 a-Si:H막은 증착속도가 증가할수록 광감도는 감소하지만 ECR플라즈마의 경우 증착속도가 증가할수록 광감도가 향상되었다. 마이크로파 출력과 사일렌/수소 희석비, 반응기내 압력등이 동일한 실험 조건에서 증착시간에 따른 막의 두께는 선형적으로 증가하고 막내에 함유된 수소의 농도는 일정하지만, 반응시간이 짧은 경우 막내에 $SiH_2$결합이 SiH결합보다 많이 형성되어 광전도도를 저하시킬 수 있다. 반응기내 압력이 증가함에 따라 박막내에 SiH결합이 증가하여 광학 에너지 갭을 줄여 광전도도를 향상시킬 수 있었으나 암전도도의 증가로 광감도는 감소하였다. 따라서 양질의 박막을 얻기 위해서는 압력이 낮고 수소기체의 양이 적은 조건에서 성장시켜야 한다.

• 한국안광학회지
• /
• 제9권2호
• /
• pp.291-299
• /
• 2004

ECR-PECVD 방법을 이용하여 ECR power, $CH_4/H_2$ 가스 혼합비와 유량, 증착시간을 고정 시켜놓고 기판 bias 전압을 변화 시켜가면서 유리 기판위에 DLC 박막을 제작하였다. Raman, FTIR 및 UV/Vis 스펙트럼을 측정하여 기판 bias 진압에 따른 이용 충돌이 박막의 특성 변화에 미치는 영향을 조사하였다. FTIR 분석결과로부터 기판 bias 전압을 증가시킬수록 이용충돌 현상이 두드러져 탄소와 결합하고 있던 수소원자들의 탈수소화 현상을 확인할 수 있었고, 박막의 두께는 bias 전압을 증가시킬수록 감소되었다. 그리고 Raman 스펙트럼으로부터 Gaussian curve fitting을 통하여 sp3/sp2의 결합수에 비례하는 D/G피크의 면적 강도비(ID/IG)는 기판 bias 전압을 증가시킬수록 증가하였다. 그리고 광 투과율은 증착시간을 길게 할수록, 기판 bias 전압을 크게할수록 감소하였으나, 박막의 밀도가 증가하고 더 매끄러운 DLC 박막이 형성되었다. 이 결과로부터 DLC 박막은 기판 bias 전압의 크기를 증가시킬수록 특성이 더 향상됨을 알 수 있었다.

• 한국세라믹학회지
• /
• 제36권2호
• /
• pp.116-121
• /
• 1999

MgO 단결성 (100) 기판 위에 0.5 wt% Nb 첨가된 전기전도성의 SrTiO3 (Nb:STO) 박막을 Pulsed Laser Deposition 법으로 제조하였다. 산소압력, 타겟과 기판거리, 기판온도, 박막증착시간 등의 박막형성 조건을 다양하게 변화시켜 Nb:STO박막의 격자상수와 박막두께의 변화를 조사하였다. $700^{\circ}C$에서 제작한 0.5 wt% Nb doped SrTiO3 박막의 배향성은 산소분압변화에 따라(100), (110)과 (111)배향이 관찰되었고, 박막제조시의 산소분압이 79.8 Pa로 증가됨에 따라 격자상수는 감소하여 벌크값인 0.390 nm에 근접하였다. 증착시간증가에 따른 박막의 두께는 증착시간에 비례하여 증가하였고, 격자상수의 변화는 거의 없었다. 타겟과 기판사이의 거리가 멀어짐에 따라 박막의 두께는 감소하였으나, 격자상수에는 큰 변화가 없었고 박막두께분포의 균일성이 향상되었다.

• 한국재료학회지
• /
• 제18권3호
• /
• pp.148-152
• /
• 2008

A new cost-effective atomic layer deposition (ALD) technique, known as Proximity-Scan ALD (PS-ALD) was developed and its benefits were demonstrated by depositing $Al_2O_3$ and $HfO_2$ thin films using TMA and TEMAHf, respectively, as precursors. The system is consisted of two separate injectors for precursors and reactants that are placed near a heated substrate at a proximity of less than 1 cm. The bell-shaped injector chamber separated but close to the substrate forms a local chamber, maintaining higher pressure compared to the rest of chamber. Therefore, a system configuration with a rotating substrate gives the typical sequential deposition process of ALD under a continuous source flow without the need for gas switching. As the pressure required for the deposition is achieved in a small local volume, the need for an expensive metal organic (MO) source is reduced by a factor of approximately 100 concerning the volume ratio of local to total chambers. Under an optimized deposition condition, the deposition rates of $Al_2O_3$ and $HfO_2$ were $1.3\;{\AA}/cycle$ and $0.75\;{\AA}/cycle$, respectively, with dielectric constants of 9.4 and 23. A relatively short cycle time ($5{\sim}10\;sec$) due to the lack of the time-consuming "purging and pumping" process and the capability of multi-wafer processing of the proposed technology offer a very high through-put in addition to a lower cost.