• 통합자연과학논문집
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• 제11권4호
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• pp.209-211
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• 2018

A zinc oxide thin film doped with aluminum was deposited by RF sputtering. The deposition temperature of the sputter chamber was kept constant at $350^{\circ}C$, the power supplied to the chamber was 75 W, the oxygen flow rate was changed to 10 sccm and 20 sccm, and the thin film deposition time was changed to 120 and 180 minutes. The structures of the deposited zinc oxide thin films were analyzed by van der Waals method using an X-ray diffractometer. As a result of X-ray diffraction, the amount of oxygen supplied to the zinc oxide thin film increased, and the surface growth of the (002), (400), (110), and (103) planes showed a change with increasing deposition time. Moreover, as the amount of oxygen supplied to the zinc oxide thin film increased, their shape was observed to be coarse, and the thin film' s particles shape was correlated with the oxygen chemical defect introduced.

• Journal of the Korean Physical Society
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• 제73권11호
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• pp.1712-1715
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• 2018

To study the applications for ferroelectric non-volatile memory and ferroelectric memristor, etc., deposition pressure dependent electric the properties of $(Hf,\;Zr)O_2$ thin films by RF sputtering deposition method were investigated. The bottom electrode was TiN thin film to produce stress effect on the formation of orthorhombic phase and top electrode was Pt thin film by DC sputtering deposition. Deposition pressure was varied along with the same other deposition conditions, for example, sputtering power, target to substrate distance, post-annealing temperature, annealing gas, annealing time, etc. The structural and electric properties of the above thin films were investigated. As a result, it is confirmed that the electric properties of the $(Hf,\;Zr)O_2$ thin films depend on the deposition pressure which affects structural properties of the thin films, such as, structural phase, ratio of the constituents, etc.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.822-825
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• 2003

Indium tin oxide (ITO) thin films were deposited by RF-magnetron sputtering method and the crystallization behavior of the films with no external heating as a function of deposition time was examined. X-ray diffraction results indicated an amorphous state of the film when the deposition time is short about 10 min. When the deposition time was increased over 20 min development of crystallization of the films is observed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 C
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• pp.845-847
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• 1999

(Ba, Sr)$TiO_3$[BST] thin films were fabricated on Pt/$TiO_2/SiO_2$/Si substrate by RF sputtering. The structural and dielectric properties of the BST thin films were investigated with the deposition time. Increasing the deposition time from 20 min. to 60 min., second phases were decreased, and EST (111), (100), (200) peaks were increased. The relative dielectric constant and dielectric loss of the EST thin films with the thickness of 3000$\AA$ were 300 and 0.018, respectively at 1[kHz]. The relative dielectric constants was decreased and dielectric losses was increased as increasing the frequency.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1994년도 춘계학술대회 논문집
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• pp.103-107
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• 1994

An experimental study was carried out to investigate the fabrication process and electrical breakdown of electrodeposted polyimide film from nonaqueous emulsion onto metal electrode surface. The thickness of imide film control led by the deposition voltage and time are proportional to the voltage or time. From the results, yeilds is proportional to the total elctrical charge flow through the electrode. When electrophoretic deposition voltage is 30 [V] deposition time is 30 sec, 40 sec, 50 sec, then the thickness of the films are 2.13 $\mu\textrm{m}$, 2.69 $\mu\textrm{m}$, 3.16 $\mu\textrm{m}$, 3.94 $\mu\textrm{m}$, respectively Electrical breakdown voltage of polyimide thin film shows very high. As film thicknes increase, the breakdown voltage are increased, but are net directly proprotional to thickness of the film.

• 대한기계학회논문집B
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• 제21권1호
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• pp.79-88
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• 1997

An analysis of unsteady heat and mass transfer in the Modified Chemical Vapor Deposition has been carried out including the effects of chemical reaction and variable properties. It was found that commonly used quasi-steady state assumption could be used to predict overall efficiency of deposition, however, the assumption would not provide detailed deposition profile. The present unsteady calculations of wall temperature profile and deposition profile have been compared with the existing experimental data and were in good agreement. The effects of variable torch speed were studied. Linearly varying torch speed case until time=120s resulted in much shorter tapered entry than the constant torch speed case.

• Journal of Welding and Joining
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• 제20권5호
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• pp.120-126
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• 2002

Ni-5%Al alloy powder is widely used as the bond coating powder to improve the adhesive strength between the substrate and coating. The important properties in the bond coating are the deposition efficiency and surface roughness. In this study, it was tried to optimize the plasma spray parameters to maximize the deposition efficiency and surface roughness. In the first step, spray current and hydrogen gas flow rate were optimized in order to increase the deposition efficiency. In the next step, the seven plasma spray variables were selected and optimized to improve both the deposition efficiency and surface roughness using the Taguchi experimental method. By these optimization, the deposition efficiency was improved from about 10 % at the frist time to 51.2 % by the optimization of spray current and hydrogen gas flow rate and finally to 65.2 % by the Taguchi experimental method. The average surface roughness was increased from about $12.9\mu\textrm{m}$ to $15.4\mu\textrm{m}$.

• 대한기계학회논문집A
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• 제24권8호
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• pp.1958-1967
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• 2000

Rapid Prototyping( RP ) has been increasingly applied in the process of design and development of new products. RP can shrink the time and expense required to bring a new product from initial concept to production. However, the necessity of using RP for short-run manufacturing is continuously driving a development of a cost-effective technique that will produce completely-finished quality parts in a very short time. To meet these demands, the improvements in production speed, accuracy materials, and cost are crucial. Thus, a new hybrid-RP system performing both deposition and machining in a station is proposed in this paper. It incorporates both material deposition in layers and material removal from the outer surface of the layer to produce the required surface finish. The new hybrid-RP system can dramatically reduce the total build time and fabricate largo-sized and freeform objects because it uses very thick layers, i.e.

• 한국진공학회지
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• 제10권2호
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• pp.201-206
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• 2001

본 연구에서는 RF 마그네트론 스퍼터링 방법을 이용하여 저탄소강 기판에 증착시킨 Fe-Ni계 합금 박막의 집합조직 발달을 조사하였다. Fe-Ni 합금 조성은 산업적 응용을 고려하여 인바합금(Invar alloy, Fe-36.5 wt%Ni)과 퍼멀로이(Permalloy, Fe-81 wt%Ni) 두 종류로 선택하였고, 증착시간을 변수로 제작하였다. 이들 합금 박막의 집합조직은 박막에서 전형적으로 나타나는 섬유집합조직(fibre texture)의 형태로 발달하였다. 인바합금 박막에서는 증착 초기에 <110>//ND 섬유집합조직이 발달하지만 증착시간이 증가함에따라 <210>//ND 섬유집합조직으로 변화하였다. 퍼멀로이 박막은 증착초기에 <221>//ND+<311>//ND의 혼합 집합조직을 나타내며 증착시간의 증가와 함께 <210>//ND 섬유집합조직으로 변화하였다. 이러한 집합조직의 변화를 박막의 미세조직의 진화와의 연관성이란 측면에서 고찰하였다.

• 한국전기전자재료학회논문지
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• 제16권5호
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• pp.441-447
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• 2003

When a SnO$_2$ thin film was deposited by thermal CVD, two different types of growth behavior that were dependent on the deposition temperature were observed. The film grown at 475$^{\circ}C$ had a wide grain size distribution and a faceted surface shape. On the other hand, the film grown at 5$25^{\circ}C$ had a relatively narrow grain size distribution and a rounded sulfate shape. The aspects of grain shape and growth behavior agree well with the theory of gram growth and a roughening transition. The charge tarrier density decreased with deposition time. According to photoluminescence measurements, the peak intensity of the spectra occurred at approximately 2.5 eV, which is related to oxygen vacancies, and decreased with increasing of deposition time. These measurement results suggest that the number of oxygen vacancies, which is related to the electrical conductivity, decrease with deposition time.