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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Vacuum Society
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Journal DOI :
The Korean Vacuum Society
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Volume & Issues
Volume 12, Issue 4 - Dec 2003
Volume 12, Issue S1 - Oct 2003
Volume 12, Issue 3 - Sep 2003
Volume 12, Issue 2 - Jun 2003
Volume 12, Issue 1 - Mar 2003
Selecting the target year
An Experimental Study on the Pumping Performance of the Multi-stage Disk-type Drag Pump
Journal of the Korean Vacuum Society, volume 12, issue 2, 2003, Pages 79~85
Experimental investigations are performed for the rarefied gas flows in a multi-stage disk-type drag pump. The pump considered in the present study consists of grooved rotors and stators. The flow-meter method is adopted to calculate the pumping speed. Compression ratios and pumping speeds for the nitrogen gas are measured under the outlet pressure range of 0.13∼533 Pa. The present experimental data show the leak-limited value of the compression ratio in the molecular transition region. The rotational speed of the pump is 24,000rpm, and nitrogen is used as a test gas. The pumping characteristics of various drag pumps are performed. The inlet pressures are measured for various outlet pressures of the test pump. The ultimate pressures for zero throughput are measured for three-stage, two-stage and single-stage disk-type, respectively.
Analysis on the Pumping Characteristics of a Commercial Cryopump
Journal of the Korean Vacuum Society, volume 12, issue 2, 2003, Pages 86~92
The pumping characteristics of a commercial UHV cryopump with a G-M refrigerator for various gases were investigated. The pumping speeds as a function of pumped amount of
, CO and the pumping capacity of
were measured and the trend was theoretically analyzed. The spectrum change of the residual gas was also investigated during cyropump operation.
Operating Characteristics of Low Vacuum Pumps
Journal of the Korean Vacuum Society, volume 12, issue 2, 2003, Pages 93~104
For evaluation of durability of low vacuum pumps, it is required to examine the performance and degradation of low vacuum pumps. Pump degradation may result from abnormalities associated with the performance in many areas of pump operation. The diagnostics method can be used to monitor the pump performance in the semi-conductor process line. Based on the mechanical defect of the pump, the dynamic response and reliability of the system for performance test, and the dynamic characteristics of the pump were experimentally assessed. The theoretical work rate for the compression process in the pump was calculated, and then the efficiency of the pump associated with the power consumption was evaluated. This analysis will be useful in detecting pump degradation with increasing the power consumption. To determine the predominant factors of pump degradation, it is important to evaluate the entire pumping system. We studied vibration, dynamic pressure, pumping speed, and power consumption of low vacuum pumps. Our results can be utilized for the future research on the evaluating technology of durability of low vacuum pumps.
Mass Selection using Reflectron in gas cluster experment.
Journal of the Korean Vacuum Society, volume 12, issue 2, 2003, Pages 105~111
In order to find out whether a reflectron can be used as a mass selector in the gas cluster experiment, computer simulation are performed using the SIMION’ program. flight paths of energetic particles in the reflectron does not depend on their mass but energy. In the case of
gas cluster, however, the position of clusters just after passing through the reflectron are spacially distributed with respect to the mass. The reason that the masses spacially distributes is the E/m ratio of clusters is constant, and it is the key reason that a reflectron can be used as a mass selector. Mass resolution does not depend on the cluster size and incident angle of clusters, and it is proportional to the incident position of clusters. This means that mass resolution can be enhanced by resizing the dimension of a reflectron. Therefore, it is concluded that a reflectron can be used as a mass selector with excellent mass resolution in the gas cluster experiment.
Comparison of characteristics of MgO films deposited by vacuum arc method with other methods.
Journal of the Korean Vacuum Society, volume 12, issue 2, 2003, Pages 112~117
MgO films is widely used in plasma display panel (PDP) technology. In this work, structural and optical properties of the MgO films deposited by e-beam evaporation, reactive magnetron sputtering, which are commercially used, and arc deposition were compared. MgO thin films were deposited on glass substrates by vacuum arc deposition equipment using a magnesium metal target at various oxygen gas flows. In order to investigate the packing density by ellipsometer, to measure reasonable erosion-rates of the MgO protective layers, we introduced an acceleration test method, namely, Ar+ ion beam induced erosion test. Also, XPS and UV test were adopted to examine the effect of the moisture on the optical transmittance of the MgO protective layers, which showed that these of MgO films by arc deposition method sustained more 90% and were insensitive to effect of the moisture. XRD and AFM have been also used to study behaviors of the structure and surface morphology.
Selectively Grown ALGaAs/GaAs Multilayers and InGaAs/GaAs Quantum Wire Structures Grown by Low Pressure MOCVD
Journal of the Korean Vacuum Society, volume 12, issue 2, 2003, Pages 118~122
Using low pressure metalorganic chemical vapor deposition (MOCVD), we have developed selectively area epitaxy (SAE). Using the developed SAE technology, we have grown AlGaAs/GaAs multi layers and InGaAs/GaAs quantum wire structures on the selectively
masked GaAs substrates. We have obtained triangular shaped AlGaAs/GaAs and InGaAs/GaAs structures with sharp tips and smooth sidewalls. To rod the optimum conditions, several growth parameters such as growth rate, V/III ratio, growth temperature, and direction of the opening stripes were investigated. The emission peak from quantum wires was observed at 975 nm. With increasing of temperature the emission intensity from side wall quantum wells decreased abruptly. But the intensity from Quantum wires decreased slowly compared to that of side wall quantum wells and it became even stronger from above 50 K.
Structuyal and physical properties of thin copper films deposited on porous silicon
Journal of the Korean Vacuum Society, volume 12, issue 2, 2003, Pages 123~129
Thin transparent Cu films in the thickness range of 10 ~ 40 nm are deposited by rf-magnetron sputtering on porous silicon (PS) anodized on p-type silicon in dark. Microstructural features of the Cu films are investigated using SEM, AFM and XRD techniques. The RMS roughness of the Cu films is found to be around 1.47 nm and the grain growth is columnar with a (111) preferred orientation and follows the Volmer-Weber mode. The photoluminescence studies showed that a broad luminiscence peak of PS near the blue-green region gets blue shifted (~0.05 eV) with a small reduction in intensity and therefore, Cu-related PL quenching is absent. The FTIR absorption spectra on the PS/Cu structure revealed no major change of the native PS peaks but only a reduction in the relative intensity. The I-V characteristic curves further establish the Schottky nature of the diode with an ideality factor of 2.77 and a barrier height of 0.678 eV. An electroluminiscence (EL) signal of small intensity could be detected for the above diode.
The Study of poly-Si Eilm Crystallized on a Mo substrate for a thin film device Application
Journal of the Korean Vacuum Society, volume 12, issue 2, 2003, Pages 130~135
Polycrystalline silicon thin films have been used for low cost thin film device application. However, it was very difficult to fabricate high performance poly-Si at a temperature lower than
for glass substrate because the crystallization process technologies like conventional solid phase crystallization (SPC) require the number of high temperature (600-
) process. The objective of this paper is to grow poly-Si on flexible substrate using a rapid thermal crystallization (RTC) of amorphous silicon (a-Si) layer and make the high temperature process possible on molybdenum substrate. For the high temperature poly-Si growth, we deposited the a-Si film on the molybdenum sheet having a thickness of 150
as flexible and low cost substrate. For crystallization, the heat treatment was performed in a RTA system. The experimental results show the grain size larger than 0.5
and conductivity of
S/cm. The a-Si was crystallized at
within 3min and improved crystal volume fraction of 92 % by RTA. We have successfully achieved a field effect mobility over 67
Fundamental characteristics of non-mass separated ion beam deposition with RE sputter-type ion source
Journal of the Korean Vacuum Society, volume 12, issue 2, 2003, Pages 136~143
In this paper, high purity RF sputter-type ion source for non-mass separated ion beam deposition was evaluated. The fundamental characteristics of the ion source which is composed of an RF Cu coil and a high purity Cu target (99.9999 %) was studied, and the practical application of Cu thin films for ULSI metallization was discussed. The relationship between the DC target current and the DC target voltage at various RF power and Ar gas pressures was measured, and then preparation conditions for Cu thin films was described. As a result, it was found that the deposition conditions of the target voltage, the target current and the Ar pressure were optimized at -300 V, 240 W and 9 Pa, respectively. The resistivity of Cu films deposited at a bias voltage of -50 V showed a minimum value of 1.8
cm, which is close to that of Cu bulk (1.67
Carbon tip growth by electron beam deposition
Journal of the Korean Vacuum Society, volume 12, issue 2, 2003, Pages 144~149
Carbon tips were grown on Si cantilevers by applying an electron beam to them directly with Scanning Electron Microscope. A carbon tip was fabricated by aligning the electron beam directly down the vertical axis of Si cantilever and then irradiating a single spot on the cantilever for a proper time in the dominant atmosphere of residual gases generated by the oil of the diffusion pump. A number of control parameters for SEM, including exposure time, acceleration voltage, emission current, and beam probe current, were allowed to make various aspect ratio feature. The growth of carbon tips was not affected by the surface morphology of substrates. We could acquired the tip whose effective length is 0.5
, bottom diameter is 90 nm and cone half angle
The growth technique of the high aspect ratio carbon tips on the tip-free cantilevers is available to reduce the complexities of fabricating sub-micron scale tips on the PZT thin film actuator integrated AFM cantilevers.