• Journal of information and communication convergence engineering
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• 제4권4호
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• pp.158-161
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• 2006

[ $Bi_2Sr_2Ca_nCu_{n+1}O_y(n{\geq}0)$ ] thin film is fabricatedvia two different processes using an ion beam sputtering method i.e. co-deposition and layer-by-layer deposition. A single phase of Bi2212 can be fabricated via the co-deposition process. While it cannot be obtained by the layer-by-layer process. Ultra-low growth rate in our ion beam sputtering system brings out the difference in Bi element adsorption between the two processes and results in only 30% adsorption against total incident Bi amount by layer-by-layer deposition, in contrast to enough Bi adsorption by co-deposition.

• 대한기계학회논문집
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• 제18권5호
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• pp.1301-1309
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• 1994

A study of heat transfer and thermophoretic particle deposition has been carried out for the Modified Chemical Vapor Deposition(MCVD) process. A new concept utilizing two torches is suggested to simulate the heating effects from repeated traversing torches. Calculation results for the wall temperatures and deposition efficiency are in good agreement with experimental data. The effects of variable properties are included and heat flux boundary condition is used to simulate the moving torch heating. A conjugate heat transfer which includes heat conduction through solid layer and heat teansfer in a gas in a tube is analyzed. Of particular interests are the effects of torch speeds and solid layer thicknesses on the deposition efficiency, rate and the tapered entry length.

• 대한기계학회논문집
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• 제18권11호
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• pp.3057-3065
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• 1994

An experimental study has been made for heat transfer and particle deposition during the Modified Chemical Vapor Deposition process which is currently utilized to manufacture high quality optical waveguides. The distributions of tube wall temperatures, rates and efficiencies of particle deposition were measured. Results indicate that the temperature distributions of the tube wall in the axial direction yield the quasi-steady form in which temperature distributions fit in one curve if the relative distance from the moving torch is used as an axial coordinate. Due to the repeated heatings from the traversing torch, the wall temperatures are shown to reach the minimum ahead of torch and it is shown that the two torch formulation suggested by Park and Choi is valid to predict this minimum temperature. Measured wall temperatures, particle deposition efficiencies and tapered entry length are compared with the previous modelling results and shown to be in agreement.

• 대한기계학회논문집
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• 제18권1호
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• pp.193-202
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• 1994

A study of heat transfer and particle deposition has been made numerically for outside vapor deposition process. Heat conduction through the two layer cylinder which consists of the target and the deposited layer is included together with heat transfer and gas jet flow onto the cylinder from the torch. Temperature and flow fields have been obtained by an iterative method and thermophoretic particle deposition has been studied. Of particlar interests are effects of the thickness of the deposited layer, the torch speed and the rotation speed of the cylinder on particle deposition flux and efficiency. Effects of buoyancy, variable properties and tube rotation are included.

• 한국기계가공학회지
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• 제12권2호
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• pp.62-67
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• 2013

The influence of internal stress and joint strength(shear, tensile) according to the deposition conditions was investigated by the Polyimide substrate and ZnO thin film. Deposition thickness and temperature affect the internal stress and the internal stress was minimum at the 60nm and $200^{\circ}C$ of the deposition conditions. Tensile strength is large at the deposition condition that shear strength is large and the shear strength was about 50% of the tensile strength. The shear strength and tensile strength were large at deposition condition that internal stress was small. Crack occurred near the joint interface of Polyimide substrate and progressed along the interface until the final fracture.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.356-356
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• 2007

Plasma immersion ion beam deposition (PIIBD) technique is a cost-effective process for the deposition of diamond like carbon thin film, the possible solid lubricant on large surface and a complex shape. We used PIIB process for the preparation of DLC thin film on $Al_2O_3$ with deposition conditions of deposition temperature range $200^{\circ}C$, working gas pressure of 1.310-1Pa. DLC thin films were coated by $C_2H_2$ ion beam deposition on $Al_2O_3$ after the ion bombardment of SiH4 as the bonding layer. Energetic bombardment of $C_2H_2$ ions during the DLC deposition to ceramic materials generated mixed layers at the DLC-Si interface which enhanced the interface to be highly bonded. Wear test showed that the low coefficient of friction of around 0.05 with normal load 2.9N and proved the advantage of the low energy ion bombardment in PIIBD process which improved the tribological properties of DLC thin film coated alumina ceramic. Furthermore, PIIBD was recognized as a useful surface modification technique for the deposition of DLC thin film on the irregular shape components, such as molds, and for the improvement of wear and adhesion problems of the DLC thin film, high temperature solid lubricant.

• 한국표면공학회지
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• 제54권3호
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• pp.139-143
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• 2021

Cr-Al-N coatings were deposited onto WC-Co substrates using a cathodic arc evaporation (CAE) system. CAE technique is recognized to be a very useful process for hard coatings because it has many advantages such as high packing density and good adhesion to metallic substrates. In this study, the influence of deposition temperature as a key process parameter on film growth behavior and mechanical properties of Cr-Al-N coatings were systematically investigated and correlated with microstructural changes. From various analyses, the Cr-Al-N coatings prepared at deposition temperature of 450℃ in the CAE process showed excellent mechanical properties with higher deposition rate. The Cr-Al-N coatings with deposition temperature around 450℃ exhibited the highest hardness of about 35 GPa and elastic modulus of 442 GPa. The resistance to elastic strain to failure (H/E ratio) and the index of plastic deformation (H³/E² ratio) were also good values of 0.079 and 0.221 GPa, respectively, at the deposition temperature of 450℃. Based on the XRD, SEM and TEM analyses, the Cr-Al-N coatings exhibited a dense columnar structure with f.c.c. (Cr,Al)N multi-oriented phases in which crystallites showed irregular shapes (50~100nm in size) with many edge dislocations and lattice mismatches.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.434-435
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• 2008

An in-situ monitoring technique for deposition process of CdS buffer layer was developed in this work. A quartz crystal microbalance (QCM) was used to measure the frequency change during the CdS deposition process and the relation ship between frequency change and film thickness and optical transmittance was investigated. The film thickness shows a linear relationship with frequency change, demonstrating that frequency change measured by QCM can be used a in-situ monitoring tool for CdS deposition process.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 춘계학술대회 논문집 반도체재료
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• pp.54-56
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• 2001

The $SiH_4$ soak step is widely used during the CVD Tungsten(W) plug deposition process on the Ti/TiN barrier metal to prevent the $WF_6$ attack to the underlayer metal. We tried to reduce or skip the time of $SiH_4$ soak process to optimize W-plug deposition process on Via. The electrical characteristics including Via resistance and the structure of W film are affected according to $SiH_4$ soak time. The elimination possibility of $SiH_4$ soak process was confirmed in the case of that the CVD W film grows on the stable Ti/TiN underlayer.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.204-205
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• 2011

In thin film silicon solar cells, p-i-n structure is adopted instead of p/n junction structure as in wafer-based Si solar cells. PECVD is a most widely used thin film deposition process for a-Si:H or ${\mu}c$-Si:H solar cells. For best performance of thin film silicon solar cell, the dopant profiles at p/i and i/n interfaces need to be as sharp as possible. The sharpness of dopant profiles can easily achieved when using multi-chamber PECVD equipment, in which each layer is deposited in separate chamber. However, in a single-chamber PECVD system, doped and intrinsic layers are deposited in one plasma chamber, which inevitably impedes sharp dopant profiles at the interfaces due to the contamination from previous deposition process. The cross-contamination between layers is a serious drawback of a single-chamber PECVD system in spite of the advantage of lower initial investment cost for the equipment. In order to resolve the cross-contamination problem in single-chamber PECVD systems, flushing method of the chamber with NH3 gas or water vapor after doped layer deposition process has been used. In this study, a new plasma process to solve the cross-contamination problem in a single-chamber PECVD system was suggested. A single-chamber VHF-PECVD system was used for superstrate type p-i-n a-Si:H solar cell manufacturing on Asahi-type U FTO glass. A 80 MHz and 20 watts of pulsed RF power was applied to the parallel plate RF cathode at the frequency of 10 kHz and 80% duty ratio. A mixture gas of Ar, H2 and SiH4 was used for i-layer deposition and the deposition pressure was 0.4 Torr. For p and n layer deposition, B2H6 and PH3 was used as doping gas, respectively. The deposition temperature was $250^{\circ}C$ and the total p-i-n layer thickness was about $3500{\AA}$. In order to remove the deposited B inside of the vacuum chamber during p-layer deposition, a high pulsed RF power of about 80 W was applied right after p-layer deposition without SiH4 gas, which is followed by i-layer and n-layer deposition. Finally, Ag was deposited as top electrode. The best initial solar cell efficiency of 9.5 % for test cell area of 0.2 $cm^2$ could be achieved by applying the in-situ plasma cleaning method. The dependence on RF power and treatment time was investigated along with the SIMS analysis of the p-i interface for boron profiles.