• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.395-398
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• 2000

Reactive radio frequency (RF)magnetron sputter with incident angle has been used to deposit AlN thin film on a crystalline Si substrate. (002)Preferred orientation of AlN thin film has been obtained at low sputtering pressure. Also it has been shown that depostion rate of AIN thin film is affected by fraction Ar and $N_2$ partial pressure. But substrate temperature didn't affect depostion rate of AIN thin film . As sputtering pressure increased preferred orientation degraded. The internal stress changed from tensile stress to compressive stress as fraction of $N_2$ partial pressure increased. At low nitrogen partial pressure cermet$^{[1]}$ AIN thin film is obtained.

• Journal of the Korean Vacuum Society
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• v.10 no.1
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• pp.9-15
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• 2001

The total pressure and partial pressure of small cavity for flat panel display have been successfully measured by using an ultra-high vacuum chamber with mass spectrometer. The total pressure in the panel was in the range of $10^{-6}$ Torr and the major partial pressure affecting increase in total pressure were those of Ar, $CH_4$and He. The baking temperature during evacuation process was very important for high-vacuum package, the total pressure and partial pressure of $CH_4$ were decreased as the increase of baking temperature.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.849-852
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• 2004

Indium tin oxide (ITO) thin films on polymeric substrates such as acryl (AC), Poly carbornate (PC), polypropylene (PP), and polyethlene terephthalate (PET) have been deposited by a do reactive magnetron sputtering without heat treatments. Sputtering parameters is an important factor for high Qualify of ITO thin films prepared on polymeric substrates. Furthermore, the material, electrical and optical properties of as-deposited ITO films are dominated by the ratio of oxygen partial pressure. As the experimental results the surface roughness of ITO films becomes rough as the oxygen partial pressure Increases. The electrical resistivity of as-deposited ITO films decreases initially, and then increases with the increase of oxygen partial pressure. The optical transmittance at visible wavelength for all polymeric substrates is above 80%.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.314-316
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• 1997

We have studied the epitaxial growth and electrical properties of $Si_{0.8}Ge_{0.2}$, films on Si substrates at $550^{\circ}C$ by LPCVD. In a low $PH_3$, partial pressure region such as below 1.25 mPa, the phosphorus doping concentration increased proportionally with increasing $PH_3$ partial pressure while the deposition rate and the Ge fraction x were constant. In a higher $PH_3$ partial pressure region, the phosphorus doping concentration and the deposition rate decreased, while the Ge fraction slightly increased. The dependence of P incorporation rate on the $PH_3$ partial pressure was similar to the phosphorus doping concentration. According to test results, it suggests that high surface coverage of phosphorus atoms suppress both the $SiH_4$ adsorption/reaction and the $GeH_4$ adsorption/reaction on the surfaces, and the effect is more stronger on $SiH_4$ than on $GeH_4$. In a higher $PH_3$ partial pressure region, the deposition is largely controlled by surface coverage effect of phosphorus atoms.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.634-637
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• 1999

The amorphous vanadium oxide as a cathode material is very preferable for fabricating high performance micro-battery. The amorphous vanadium oxide cathode is preferred over the crystalline form because three times more lithium ions can be inserted into the amorphous cathode, thus making a battery that has a higher capacity. The electrochemical properties of sputtered films are strongly dependent on the oxygen partial pressure in the sputtering gas. The effect of different oxygen partial pressure on the electrochemical properties of vanadium oxide thin films formed by r.f. reactive sputtering deposition were investigated. The stoichiometry of the as-deposited films were investigated by Auger electro spectroscopy. X-ray diffraction and atomic force microscopy measurements were carried out to investigate structural properties and surface morphology, respectively. For high oxygen partial pressure(>30% ), the films were polycrystalline V$_2$O$_{5}$ while an amorphous vanadium oxide was obtained at the lower oxygen partial pressure(< 15%). Half-cell tests were conducted to investigate the electrochemical properties of the vanadium oxide film cathode. The cell capacity was about 60 $\mu$ Ah/$\textrm{cm}^2$ m after 200 cycle when oxygen partial pressure was 20%. These results suggested that the capacity of the thin film battery based on vanadium oxide cathode was strongly depends on crystallinity.y.

• Journal of the Korean Ceramic Society
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• v.50 no.4
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• pp.288-293
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• 2013

Zn-In-Sn-O films were prepared at room temperature by combinatorial RF-magnetron co-sputtering system. The cationic contents of the films were varied using a compositionally combinatorial technique. The effects of the oxygen partial pressure and film compositionon the structural and electrical properties were investigated. The Zn-In-Sn-O films deposited at Ar gas atmosphere showed an amorphous phaseirrespective of the film composition. However, the amorphous Zn-In-Sn-O films with a Zn content below 30.0 at% were converted into a bixbyite type-ITO polycrystalline phase with an increase in the oxygen partial pressure. The resistivity, carrier concentration, and Hall mobility were strongly affected by the oxygen partial pressure and chemical composition of the film. At sufficiently high carrier densities above $5{\times}10^{18}cm^{-3}$, the conduction behavior of amorphous Zn-In-Sn-O film changes from thermally activated to degenerate band conduction accompanied with high mobility.

• Progress in Superconductivity and Cryogenics
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• v.18 no.1
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• pp.64-68
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• 2016

High Temperature Superconductor power cable systems are being developed actively to solve the problem of increasing power demand. With increases in the unit length of the High Temperature Superconductor power cable, it is necessary to develop highly efficient and reliable cryogenic pumps to transport the coolant over long distances. Generally, to obtain a high degree of efficiency, the cryogenic pump requires a high pressure rise with a low flow rate, and a partial emission type pump is appropriate considering its low specific speed, which is different from the conventional centrifugal type, full emission type. This paper describes the design of a partial emission pump to circulate subcooled liquid nitrogen. It consists of an impeller, a circular case and a diffuser. The conventional pump and the partial emission pump have different features in the impeller and the discharge flow passage. The partial emission pump uses an impeller with straight radial blades. The emission of working fluid does not occur continuously from all of the impeller channels, and the diffuser allows the flow only from a part of the impeller channels. As the area of the diffuser increases gradually, it converts the dynamic pressure into static pressure while minimizing the loss of total pressure. We used the known numerical method for the optimum design process and made a CFD analysis to verify the theoretical performance.

• Korean Journal of Materials Research
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• v.19 no.1
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• pp.13-17
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• 2009

A semi-empirical method to estimate the surface tension of molten alloys at different oxygen partial pressures is suggested in this study. The surface tension of molten Ag-Sn and Ag-Cu alloys were calculated using the Butler equation with the surface tension value of pure substance at a given oxygen partial pressure. The oxygen partial pressure ranges were $2.86{\times}10^{-12}$－$1.24{\times}10^{-9}$ Pa for the Ag-Sn system and $2.27{\times}10^{-11}$－$5.68{\times}10^{-4}$ Pa for the Ag-Cu system. In this calculation, the interactions of the adsorbed oxygen with other metallic constituents were ignored. The calculated results of the Ag-Sn alloys were in reasonable accordance with the experimental data within a difference of 8%. For the Ag-Cu alloy system at a higher oxygen partial pressure, the surface tension initially decreased but showed a minimum at $X_{Ag}$ = 0.05 to increase as the silver content increased. This behavior appears to be related to the oxygen adsorption and the corresponding surface segregation of the constituent with a lower surface tension. Nevertheless, the calculated results of the Ag-Cu alloys with the present model were in good agreement with the experimental data within a difference of 10%.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.57.1-57.1
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• 2010

ITO(Indium Tin Oxide)는 전도도와 투과도 특성이 뛰어나 디스플레이, 태양전지, LED 등 여러 산업에서 전극 물질로 널리 사용 되어져 왔다. 최근 ITO의 사용이 급격히 증가하면서 이에 대한 연구가 활발히 진행되고 있다. ITO는 막의 특성을 좋게 하기 위하여 증착 시 Ar gas와 함께 $O_2$가스를 첨가하기도 한다. 본 연구에서는 산소 분압에 따른 ITO 박막의 전기적, 광학적 특성에 대하여 연구하였다. Corning사의 eagle 2000 glass 기판위에 스퍼터링을 이용하여 ITO layer를 증측하였고, 증착시, $O_2$ partial pressure를 0 - 0.5%까지 0.1% 간격으로 가변하였다. 증착된 샘플은 Sinton사의 UV-vis 장비를 이용하여 광학적 특성을 측정하였고, Hall measurement 장비를 이용하여 전기적 특성을 측정하였다. ITO 박막은 $O_2$의 partial pressure가 증가할수록 향상된 전기적, 광학적 특성을 나타내었다.

• Journal of the Korean Vacuum Society
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• v.12 no.S1
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• pp.83-87
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• 2003

Zirconium oxide films have been synthesized by radio-frequency magnetron sputtering deposition on n-Si(001) substrate with metal zirconium target at variant $O_2$ partial pressures. The influences of $O_2$ partial pressures of the morphology, deposition rate, microstructure, and the dielectric constant of $ZrO_2$ have been discussed. The results show that deposition rate of $ZrO_2$ films decreases, the roughness, and the thickness of the native $SiO_2$ interlayer increases with the increase of $O_2$ partial pressure. $ZrO_2$ films synthesized at low $O_2$ partial pressure are amorphous and monoclinic polycrystalline in nanometer scale at low $O_2$ partial pressure. The relative dielectrics of $ZrO_2$ films are in the range of 12 to 25.